α-arylethylpiperazine derivatives as neurokinin antagonists

ABSTRACT

The invention relates to new α-arylethylpiperazine of the formula 
                 
 
wherein
         Z represents 0 or S;   n′ represents 1 or 2;   R 2  represents a hydrogen atom or a methyl group;   W, Ar 1  and Ar 2  represent various substituents as defined herein;
 
or non-toxic pharmaceutically acceptable salt, individual optical isomer, or individual diastereoisomer thereof, which are useful as neurokinin receptor antagonists (NK 1  antagonists). It also relates to processes for their preparation and use in methods for treatment of asthma and/or allergic rhinitis.

The present invention relates to new α-arylethylpiperazine derivatives, which are useful as neurokinin receptor antagonists (NK₁ antagonists). It also relates to processes for the preparation of said α-arylethylpiperazine derivatives, to their use for the prevention and/or treatment of a condition associated with pathogical levels of substance P in a patient and to pharmaceutical compositions containing them.

Neurokinins (also called NKs or tachykinins) are a family of small peptides which are released from neuronal sensory afferents and which share a common carboxy-terminal region Phe-X-Gly-Leu-Met-NH₂; in mammals, the main members are substance P (SP), neurokinin A (NKA, also known as substance K) and neurokinin B (NKB, also known as neuromedin K), which act as neurotransmitters and neuromodulators (C. A. Maggi, R. Patacchini, P. Rovero, A. Giachetti, J. Auton. Pharmacol. (1993) 13, 23-93). These three types of neurokinins possess different degrees of potency; their endogenous agonist effect occurs via specific receptors. Three types of neurokinin receptors have been identified: NK₁ (SP-preferring), NK₂ (NKA-preferring) and NK₃ (NKB-preferring), which are widely distributed throughout the central nervous system (CNS) and peripheral nervous system (E. Burcher, C. J. Mussap, J. A. Stephenson, Tachykinin Receptors, Ed. Buck S H, Humana Press, Totowa, N.J. (1994), 125-163; J. E. Maggio, P. W. Mantyh, L. L. Iversen, ibid, 1-38).

Neurokinins have been described to be implicated in numerous physiological and pathological processes such as neuronal modulation, plasma protein extravasation, mast cell degranulation and mitogenic effects (C. A. Maggi, R. Patacchini, P. Rovero, A. Giachetti, J. Auton. Pharmacol. (1993) 13, 23-93). In the peripheral nervous system, evidence suggests that neurokinins released from peripheral endings of sensory nerves are responsible for the phenomenon of neurogenic inflammation. Within the CNS, SP may serve as a neuromodulator of inputs from unmyelinated C-fibers involved in nociception to the central terminals of primary sensory neurones in the brainstem and spinal cord dorsal horn, suggesting a clinical utility for NK₁ receptor antagonists in the treatment of pain, particularly migraine (S. M. Moussaoui et al., Eur. J. Pharmacol. (1993) 238, 421-4; F. M. Curtler et al., Neuroscience (1995) 64, 741-50). SP-containing afferent nerve fibers also inervate the brain region of the nucleus tractus solitarius, an area involved in the control of emesis, suggesting the use of NK₁ receptor antagonists as antiemetics (F. D. Tattersall, W. Rycroft, R. G. Hill, R. J. Hargreaves, Neuropharmacology (1994) 33, 259-60; J. W. Watson, S. F. Gonsalves, A. A. Fossa et al., Br. J. Pharmacol. (1995) 115, 84-94). In the lung, neurokinins are released as a consequence of inflammatory processes and cause plasma protein extravasation, oedema formation, increased blood flow and mucus hypersecretion via NK₁ receptors (J. A. Lowe, Emerging Drugs (1996) 1-18). Thus selective NK₁ antagonists may have a potential therapeutic indication in the treatment of pulmonary diseases, in particular asthma and bronchitis.

There is also evidence supporting a role for SP in allergic rhinitis. First, in patients with allergic rhinitis, nasal SP content significantly increases immediately after nasal allergen challenge. Moreover, at the clinical peak of the late allergic reaction, SP levels are also raised (B. L. Mosimann et al., J. Allergy Clin. Immunol. (1993) 92, 95-104). Second, in allergic rhinitis, intranasal SP challenges induce vasodilatation, plasma leakage and recruitment of inflammatory cells (I. Fajac et al., Allergy (1995) 50, 970-5; A. Konn et al., Ann. Otol. Rhino. Laryngol. (1996) 105, 648-53) and the reduction of SP content in nasal secretions (after chronic capcaisin treatment) is related to the reduction of the clinical symptoms of allergic rhinitis (R. Zhang et al., Chung Hua Erh Pi Yen Hou Ko Tsa Chih (1995) 30, 163-5). Third, SP enhances antigen-evoked mediator release from human nasal mucosa by interaction with mast cells (C. R. Baumgarten C. R. et al, Peptides (1996) 17, 25-30).

The first potent non-peptide NK₁ receptor antagonists, i.e. CP-96,345 (R. M. Snider, S. J. W. Constantine, J. A. Lowe et al. Science (1991) 251, 435-7) and RP-67,580 (J. F. Peyronel, A. Truchon, C. Moutonnier, C. Garret, Bioorg. & Med. Chem. Lett. (1992) 2, 37-40) were discovered in 1991-1992. While CP-96,345 exhibited good selectivity for NK₁ receptors with respect to NK₂ and NK₃ receptors, it showed significant affinity for a number of ion channels, notably the verapamil-sensitive L-type Ca²⁺ binding site (M. Caeser, G. R. Seabrook, J. A. Kemp, Br. J. Pharmacol. (1993) 109, 918-24). Such properties are undesirable from a therapeutic point of view because they are indicative of potential cardiovascular side-effects. This finding led to the discontinuation of further preclinical and clinical investigation of the compounds. Structure-activity relationship (SAR) modifications based on CP-96,345 provided other clinical candidates. For example CP-99,994 was determined to have good NK₁ selectivity and lower interaction with the verapamil-sensitive L-type Ca²⁺ binding site than CP-96,345 (T. Rosen, T. F. Seegar, S. McLean et al., J. Med. Chem. (1993) 36, 3197-3201). It was evaluated in phase II clinical trials for asthma but first trials were reported unsuccessful, possibly due to its poor bioavailability (J. A. Lowe, Emerging Drugs (1996) 1-18; J. V. Fahy, H. F. Wong, P. Gepetti et al., Am. J. Respir. Crit. Care Med. (1995) 152, 879-884).

As to RP-67,580, it exhibited some NK₁ affinity. Molecular modifications by SAR led to improved candidates, such as RP-100,893, for example. It has been evaluated in clinical trials for the treatment of migraine; however, activity after oral administration was reported to be no better than placebo activity, possibly due to poor brain penetration (C. J. Swain, R. J. Hargraves, Annual Reports in Medicinal Chemistry, Vol. 31, Bristol, J. A. (Ed.) Academic Press: San Diego (1996) 111-120).

In view of the undesirable side-properties of these first non-peptide neurokinin antagonists, intensive work has been carried out by various teams in order to find other non-peptide NK₁ antagonists.

In particular, patent application WO 94/14767 and U.S. Pat. No. 5,624,947 disclose aromatic compounds presented as valuable in the treatment of a wide variety of clinical conditions which are characterised by the presence of an excess of tachykinins, in particular substance P, one of these compounds being the hydrochloride salt of (±)-1-[(3,5-bistrifluoromethylphenyl)methyloxy]-2-N-morpholino-2-phenylethane. Patent application DE 19520499 discloses disubstituted piperazines and piperidines presented for their neurokinin receptor antagonist properties. Amongst the most promising candidates, this document discloses 3,5-bistrifluoromethylbenzyl-[2-(2-methoxyphenyl)-2-(4-(2-phenylethyl)-piperazin-1-yl)-ethyl]-amine, 3,5-bistrifluoromethylbenzyl-[2-(2-methoxyphenyl)-2-(4-cycloheptylpiperazin-1-yl)-ethyl]-amine and 3,5-bistrifluormethylbenzyl-[2-(2-methoxyphenyl)-2-(4piperidin-1-yl)-piperidin-1-yl)-ethyl]-amine.

We have now found other non-peptide selective NK₁ receptor antagonists with no or low affinity for Ca²⁺ ion channels and which exhibit good oral bioavailability and duration of action, these compounds exhibiting useful properties for the prevention and/or treatment of a condition associated with pathological levels of substance P in a patient.

Accordingly, the present invention relates to new α-arylethylpiperazine derivatives of formula I

-   -   wherein     -   Z represents O or S;     -   n′ represents 1 or 2;     -   R² represents a hydrogen atom or a methyl group;     -   W represents         -   (i) a cyclohexyl group substituted by a COOH, 2-phenylacetic             acid or alkyl 2-phenylacetate group,         -   (ii) a group of formula         -    wherein r represents 1, 2 or 3 and Q represents OH or             —NH—CO—CH₃, or         -   (iii) a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— in which             -   R¹ represents a CN, CONR^(i)R^(ii), CONHOH, CONHCH₂CO₂H,                 CONHCH₂CO₂alkyl, CONHSO₂alkyl, CONHSO₂phenyl,                 CONHSO₂tolyl, COOH, COOalkyl, OH, SO₃H,                 PO(OR^(iii))(OR^(iv)) group, a mono-, di- or                 tri-substituted phenyl group in which the substituent is                 selected from COOH, COOalkyl or OCH₃, a heteroaryl, a                 tetrazole, a morpholine, a thiomorpholine, a                 thiomorpholine S,S-dioxide, a phthalimide group or a                 triazolone of formula             -   wherein R^(i), R^(ii), R^(iii) and R^(iv) independently                 represent a hydrogen atom or an alkyl group;             -   X represents a single bond, an oxygen atom or a                 methylene group;             -   m represents 1 or 2, provided that m is not 1 when X is                 O;             -   n represents 0, 1 or 2, provided that N is not 0 or 1                 when X represents O and R1 represents OH;     -   Ar¹ represents a phenyl, aryl, heteroaryl, or mono-, di- or         tri-substituted phenyl group in which the substituents are         selected from a halogen atom, an alkyl, trifluoromethyl,         hydroxy, alkoxy, SCH₃, CN, NO₂, CONH₂, COOH, COOalkyl or amino         group, or mono-substituted heteroaryl group in which substituent         is a halogen atom;     -   Ar² represents a substituted phenyl group of formula         -   in which             -   R³ represents a halogen atom, an alkyl, alkoxy,                 trifluoromethyl, COOH, CN, COOalkyl or CONH₂ group;             -   R⁴ represents a halogen atom, a trifluoromethyl or alkyl                 group;             -   p and q independently represent 0, 1, 2 or 3;     -   or a group of formula         -   -   in which R⁵ represents a halogen atom;                 all alkyl and alkoxy groups being linear or branched and                 having from 1 to 4 atoms of carbon,                 as well as non-toxic pharmaceutically acceptable salts,                 individual optical isomers, individual diastereoisomers                 or prodrugs thereof.

The present invention also relates to new α-arylethylpiperazine derivatives of formula II

wherein

-   -   Z represents O or S;     -   n′ represents 1 or 2;     -   R² represents a hydrogen atom or a methyl group;     -   Ar¹ represents a phenyl, aryl, heteroaryl, or mono-, di- or         tri-substituted phenyl group in which the substituents are         selected from a halogen atom, an alkyl, trifluoromethyl,         hydroxy, alkoxy, SCH₃, CN, NO₂, CONH₂, COOH, COOalkyl or amino         group, or a mono-substituted heteroaryl group in which         substituent is a halogen atom;     -   Ar² represents a substituted phenyl group of formula     -    in which         -   R³ represents a halogen atom, an alkyl, alkoxy,             trifluoromethyl, COOH, CN, COOalkyl or CONH₂ group;         -   R⁴ represents a halogen atom, a trifluoromethyl or alkyl             group;         -   p and q independently represent 0, 1, 2 or 3, provided that             p is not 0 and q is not 0 when Ar¹ is a phenyl             para-substituted by a fluorine atom;     -   or a group of formula     -    in which R⁵ represents a halogen atom;     -   all alkyl and alkoxy groups being linear or branched and having         1 to 4 atoms of carbon;         as well as non-toxic pharmaceutically acceptable salts,         individual optical isomers or individual diastereoisomers         thereof.

The expression halogen atom as used herein includes fluorine, chlorine, bromine and iodine atoms.

The expression aryl as used herein includes 1-naphtyl or 2-naphtyl groups.

The expression heteroaryl as used herein includes pyridine, quinoline, isoquinoline, furan, thiophen, benzofuran, benzothiofuran or indole.

Preferred compounds according to the present invention are α-arylethylpiperazine derivatives of formula I′

-   -   wherein         -   Z represents an oxygen atom;         -   n′ represents 1;         -   R² represents a hydrogen atom or a methyl group;         -   W represents             -   (i) a cyclohexyl group substituted by COOH, or             -   (ii) a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— in                 which                 -   R¹ represents CN, CONHSO₂alkyl, COOH, COOalkyl,                     SO₃H, PO(OH)₂, a phenyl group mono-substituted by                     COOH, a tetrazole group or a triazolone of formula                 -   X represents a single bond, an oxygen atom or a                     methylene group                 -   m represents 1 or 2, provided that m is not 1 when X                     is an oxygen atom;                 -   n represents 0, 1 or 2, provided that n is not 0 or                     1 when X represents an oxygen atom and R¹ represents                     OH;         -   Ar¹ represents phenyl, a mono-, di- or tri-substituted             phenyl group in which the substituents are selected from a             halogen atom, an alkyl group, CN or NO₂;         -   Ar² represents a substituted aryl group of formula         -   in which             -   R³ represents a halogen atom or a trifluoromethyl group;             -   p represents 0, 1, 2 or 3;     -   the alkyl groups being linear or branched and having 1 to 4         atoms of carbon, as well as non-toxic pharmaceutically         acceptable salts, individual optical isomers, individual         diastereoisomers or prodrugs thereof.

Particularly preferred compounds according to the invention include

-   [2-(4-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-piperazin-1-yl)-ethoxy]-acetic     acid; -   (4-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-piperazin-1-yl)-acetic     acid; -   4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic     acid; -   6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic     acid; -   {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetonitrile; -   3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-propane-1-sulfonic     acid; -   5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-pentanoic     acid; -   (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic     acid; -   {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic     acid; -   {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(3,4,5-trifluoro-phenyl)-ethyl]-piperazin-1-yl}-acetic     acid; -   4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-benzoic     acid; -   {4-[2-(3,5-Dibromo-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic     acid; -   {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-para-tolyl-ethyl]-piperazin-1-yl}-acetic     acid; -   (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethyl)-phosphonic     acid; -   {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2,3-difluoro-phenyl)-ethyl]-piperazin-1-yl}acetic     acid; -   {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2-nitro-phenyl)-ethyl]-piperazin-1-yl}-acetic     acid; -   N-[(2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetyl]-methanesulfonamide; -   {4-[2-(3,5-Dichloro-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic     acid; -   {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic     acid; -   5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-2,4-dihydro-[1,2,4]triazol-3-one; -   1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-4-[4-(1H-tetrazol-5-yl)-butyl]-piperazine; -   1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-4-[2-(1H-tetrazol-5-ylmethoxy)-ethyl]-piperazine; -   1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-fluoro-phenyl)-ethyl]-4-[4-(1H-tetrazol-5-yl)-butyl]-piperazine; -   1-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-4-[4-(1H-tetrazol-5-yl)-butyl]-piperazine; -   1-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-4-[5-(1H-tetrazol-5-yl)-pentyl]-piperazine; -   (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic     acid isobutyl ester; -   3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-benzoic     acid; -   4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-butyric     acid;     -   as well as non-toxic pharmaceutically acceptable salts,         individual optical isomers or individual diastereoisomers         thereof.

The present invention also relates to non-toxic pharmaceutically acceptable salts of α-arylethylpiperazine derivatives of formula I. Such pharmaceutically acceptable salts

include non-toxic pharmaceutically acceptable acid addition salts of α-arylethylpiperazine derivatives of formula I. As examples there may be mentioned salts of mineral acids, such as hydrochloric, hydrobromic, sulfuric, nitric and phosphoric acids and salts of organic acids, such as acetic, citric, tartaric, benzoic, salicylic and maleic acids. Anhydrous and hydrated forms of such salts are also encompassed by the present invention.

When the compound of formula I carries an acid moiety, pharmaceutically acceptable salts of compounds of formula I also include metal salts such as alkaline metal salts (such as sodium, potassium) or alkaline earth metal salts (such as calcium or magnesium salts).

When the molecule contains one or several asymmetric carbon atoms, the compound of formula I may either be in the form of a racemic mixture, in the form of one of its individual enantiomers or in the form of one of its individual diastereoisomers. It is to be understood that all such individual enantiomers and diastereoisomers and mixtures thereof in any proportion are encompassed within the scope of the present invention.

The term prodrugs as used herein refers to compounds which are rapidly transformed in vivo into the compounds of general formula I (see T. Higuchi and V. Stella, “Pro-drugs as Novel Delivery Systems”, Vol 14 of the A.C.S. Symposium Series, and Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987 for a detailed discussion).

The α-arylethylpiperazine derivatives of formula I may be prepared by one of the following processes:

-   (a) when, in formula I, Ar¹ represents a phenyl, aryl or heteroaryl     group, a mono-, di- or trisubstituted phenyl group in which the     substituents are selected from a halogen atom, an alkyl,     trifluoromethyl, alkoxy, SCH₃ or NO₂ group, or a mono-substituted     heteroaryl group in which substituent is a halogen atom, Ar², Z, R²     and n′ having the same meanings as given above in general formula I,     and, furthermore, -   (a.1) when, in formula I, W represents     -   (i) an alkyl 2-phenylacetate group,     -   (ii) a group of formula     -    wherein r represents 1, 2 or 3 and Q represents OH, or     -   (iii) a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— in which R¹         represents a CN, CONR^(i)R^(ii), COOalkyl, OH, SO₃H or         PO(OR^(iii))(OR^(iv)) group, a mono-, di- or tri-substituted         phenyl group in which the substituent is COOalkyl or OCH₃, a         pyridine, morpholine, thiomorpholine,         thiomorpholine-(S,S)-dioxide or phthalimide group, wherein R^(i)         and R^(ii) represent a hydrogen atom or an alkyl group and         R^(iii) and R^(iv) represent an alkyl group, n, m and X having         the same meanings as given above in general formula I,     -   an α-arylethylpiperazine of formula II is reacted with a         compound of formula III according to the equation     -   wherein Ar¹, Ar², Z, R², n′ and W have the same meanings as         stated above and Hal represents a halogen atom, preferably a         chlorine, bromine or iodine atom.

This reaction is known per se and is generally carried out in an inert solvent, for example toluene, dimethylformamide, an alcohol or dichloroethane, in the presence of an acid acceptor, such as a tertiary organic base, for example triethylamine, or an inorganic base, for example sodium carbonate, sodium hydrogenocarbonate, potassium carbonate or potassium hydrogenocarbonate.

-   (a.2) when, in formula I, W represents     -   (i) 2-phenylacetic acid, or     -   (ii) a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)—, in which     -   R¹ represents CONHCH₂CO₂H, COOH, PO(OH)(OEt), PO(OH)₂ or a         mono-, di- or trisubstituted phenyl group in which the         substituents are COOH, n, m and X having the same meanings as         given above in general formula I, the corresponding compound of         formula I wherein W is     -   (i) an alkyl 2-phenylacetate or     -   (ii) a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— in which R¹         represents CN, CONH₂, CONHCH₂CO₂alkyl, COOalkyl, PO(OEt)₂ or a         mono-, di- or tri-substituted phenyl group in which the         substituent is COOalkyl, n, m and X having the same meanings as         given above in general formula I,     -   is hydrolysed in an aqueous, alcoholic or aqueous-alcoholic         medium by an acid or a base. -   (a.3) when, in formula I, W is a group of formula     R¹—(CH₂)_(n)—X—(CH₂)_(m)— wherein n, m and X have the same meaning     as given above in general formula I, and     -   a.3.1. R¹ is CN, the corresponding compound of formula I in         which R¹ is CONH₂ is dehydrated;     -   a.3.2. R¹ is CONH₂, the corresponding compound of formula I in         which R¹ is COOalkyl is ammonolyzed;     -   a.3.3. R¹ is COOalkyl or CONHCH₂COOalkyl, the corresponding         compound of formula I in which R¹ is COOH or CONHCH₂COOH is         esterified;     -   a.3.4. R¹ is CONR^(i)R^(ii), R^(i) and R^(ii) independently         representing a hydrogen atom or an alkyl group, at least one of         R^(i) or R^(ii) being an alkyl group, the corresponding compound         of formula I in which R¹ is COOH or COOalkyl is aminolyzed.

These transformations may be performed under any appropriate conditions known to the person skilled in the art.

-   -   (a.4) when, in formula I, W is a group of formula         R¹—(CH₂)_(n)—X—(CH₂)_(m)— wherein R¹ represents a triazolone of         formula     -    and n, m and X have the same meanings as in general formula I,         an α-arylethylpiperazine of formula II     -   wherein Ar¹, Ar², Z, R² and n′ have the same meanings as stated         above is reacted under heating with a (chloromethyl)amidrazone         of formula XIX     -   wherein n, m and X have the same meanings as stated above.

This reaction may be carried out following the method described in Ladduwahetty T. et al., J. Med. Chem. (1996), 39, 2907-2914.

-   (a.5) when, in formula I, W is a group of formula     R¹—(CH₂)_(n)—X—(CH₂)_(m)— wherein R¹ is a tetrazole, n, m and X     having the same meanings as given above in general formula I, the     corresponding compound of formula I wherein R¹ is CN is reacted with     azidotrimethylsilane in the presence of dibutyltin oxide.     -   This transformation may be performed according to the procedure         disclosed in Wittenberger S. et al., J. Org. Chem. (1993), 58,         4139-4141 or Owens A. P. et al., Bioorg. Med. Chem. Letters         (1998), 8, 51-56. -   (a.6) when, in formula I, W is a group of formula     R¹—(CH₂)_(n)—X—(CH₂)_(m)— wherein R¹ represents CONHSO₂alkyl,     CONHSO₂phenyl or CONHSO₂tolyl, n, m and X having the same meanings     as given above in general formula I, the corresponding compound of     formula I in which R¹ is COOH is reacted with a sulfonamide of     formula R^(v)—SO₂—NH₂ in which R^(v) represents an alkyl, phenyl or     4-methylphenyl group. This reaction may be performed under     conventional peptide synthesis conditions such as, for example,     those described in “Principles of Organic Synthesis” Volume 16, M.     Bodansky, Springer-Verlag Berlin Heidelberg New York Tokyo 1984. -   (a.7) when, in formula I, W is a group of formula     R¹—(CH₂)_(n)—X—(CH₂)_(m), wherein R¹ represents CONHSO₂alkyl,     CONHSO₂phenyl or CONHSO₂tolyl, n=0, X═O and m=2, the corresponding     α-arylethylpiperazine of formula I wherein R¹ is HO—(CH₂)_(m) is     reacted with the compound of formula R—SO₂—N═C═O in which R     represents alkyl, phenyl or 4-methylphenyl.

This reaction may, for example, be carried out under the conditions described in Friesen R. W. and Phipps L. G., Synlett (1991), 420-422.

-   (a.8) when, in formula I, W is a group of formula     -   wherein Q═NH(CO)CH₃, the corresponding compound of formula I in         which Q is OH is reacted with acetonitrile in the presence of         acid. The conditions used for this reaction are for example         those disclosed in European Patent application 474,561 (page         37).

The starting compound of formula I in which Q═OH may be obtained by method a.1 described above.

-   (a.9) when, in formula I, W is a cyclohexyl group substituted by     COOH, the corresponding compound of formula I in which W is a     cyclohexyl group substituted by COOalkyl is hydrolysed in an     aqueous, alcoholic or aqueous-alcoholic medium in presence of an     acid or a base. The starting compound of formula I in which W is a     cyclohexyl group substituted by COOalkyl may be obtained by     reductive amination of a cyclohexanone of formula XXVII with a     piperazine of formula II according to the equation

In these formulae, Ar¹, Ar², Z, R² and n′ have the same meanings as stated above. This reaction may for example be carried out according to the procedure disclosed in Maryanoff B. E. et al., J. Med Chem. (1981), 24 (1), 79-88.

-   (a.10) when, in formula I, W is a group of formula     R¹—(CH₂)_(n)—X—(CH₂)_(m) wherein R¹ represents CONHOH, n, m and X     having the same meanings as given above in general formula I, a     corresponding compound of formula I wherein R¹ represents COOH is     coupled with the compound of formula XXIX     -   followed by treatment with trifluoroacetic acid.

This reaction may be carried out according to the procedure disclosed in Barlaam B. et al., Tetrahedron Lett. (1998), 39, 7865-7868.

-   (b) when, in formula I, Ar1 is a mono-, di- or tri-substituted     phenyl group in which the substituents are COOCH₃, Ar², Z, R² and n′     have the same meanings as given above in general formula I and W is     a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— wherein R¹ represents     COOalkyl, n, m and X having the same meanings as given above in     general formula I, the corresponding compound of formula I in which     Ar¹ is a mono-, di- or tri-substituted phenyl group in which the     substituents are bromine atoms is submitted to methoxycarbonylation     by carbon monoxide treatment in the presence of palladium(II)     acetate, 1,3-bis(diphenylphosphino)propane and triethylamine in     methanol (see Lin C. H. et al., J. Med . Chem. (1993), 36, 2208-2218     for detailed conditions). -   c) when, in formula I, Ar¹ is mono-, di- or tri-substituted phenyl     group in which the substituents are CN, Ar², Z, R² and n′ have the     same meanings as given above in general formula I and W is a group     of formula R¹—(CH₂)_(n)—X—(CH₂)_(m) wherein R¹ represents COOalkyl,     n, m and X having the same meanings as in general formula I, a     corresponding compound of formula I Ar¹ is a mono-, di- or     tri-substituted phenyl group in which the substituents are Bromine     atoms is reacted with zinc cyanide (see Tschaen D. M. et al., J.     Org. Chem. (1995), 60, 4324-4330 for detailed conditions). -   (d) when in formula I, Ar¹ is a mono-, di- or tri-substituted phenyl     group in which the substituents are COOH or CONH₂, Ar², Z, R² and n′     have the same meanings as given above in general formula I, the     corresponding compound of formula I in which Ar¹ is a mono-, di- or     tri-substituted phenyl group in which the substituents are COOalkyl     is hydrolysed or ammonolyzed; optionally, this transformation may     take place simultaneously with hydrolysis or ammonolysis of another     COOalkyl group of the compound of formula I; -   (e) when in formula I, Ar¹ is a mono-, di- or tri-substituted phenyl     group in which the substituents are COOH, Ar², Z, R² and n′ have the     same meanings as given above in general formula I, the corresponding     compound of formula I in which Ar¹ is a mono-, di- or     tri-substituted phenyl group in which the substituents are CN is     hydrolysed; optionally, this transformation may take place     simultaneously with the hydrolysis of another CN group of the     compound of formula I: -   (f) when in formula I, Ar¹ is a mono-, di- or tri-substituted phenyl     group in which the substituents are CN, Ar², Z, R² and n′ have the     same meanings as given above in general formula I and W is a group     of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— wherein R¹ represents COOH and     n, m and X have the same meaning as stated above for general formula     I, the corresponding compound of formula I in which R¹ is COOalkyl     is hydrolysed, as described in (a2). -   (g) when, in formula I, Ar¹ is a mono-, di- or tri-substituted     phenyl group in which the substituents are NH₂ and W is a group of     formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— wherein R¹ represents COOH or     COOalkyl, Ar², Z, R², n′, n, m and X having the same meanings as     given above in general formula I, the corresponding compound of     formula I in which Ar¹ is a mono-, di- or tri-substituted phenyl     group in which the substituents are NO₂ is reduced. Any conditions     known for the reduction of nitro groups into amino groups may be     used for this transformation. -   (h) when, in formula I, Ar¹ is a mono-, di- or tri-substituted     phenyl group in which the substituents are OH, W, Ar², Z, R² and n′     having the same meaning as given above in general formula I, the     corresponding compound of formula I in which Ar¹ is a mono-, di- or     tri-substituted phenyl group in which the substituents are OP′,     wherein P′ is a protecting group, is deprotected. The protecting     group P′ may be any suitable alcohol protecting group such as, for     example, a methoxyethoxymethyl (MEM), a tetrahydropyranyl (THP), an     allyl or a benzyl group. For more details concerning deprotection     methods, see “Protective Groups in Organic Chemistry”, J. F. W.     Omie, Plenum Press, London and New York, 1973 and “Protective Groups     in Organic Synthesis”, Th. W. Greene, John Wiley & Sons, 1981. -   (i) optionally, the α-arylethylpiperazine derivative of formula I     so-obtained is converted into one of its non-toxic pharmaceutically     acceptable salts. The non-toxic pharmaceutically acceptable salts     can be prepared from α-arylethylpiperazine derivatives of formula I     by methods which are known per se.

The compounds of formula I which are in the form of a mixture of individual optical isomers are either obtained from optically pure starting materials or by separation of a mixture of optical isomers of the compound of general formula I by conventional resolution methods, including chromatographical methods.

The present invention also encompasses compounds of formula II which are useful intermediates for the preparation or compounds of formula I.

The present invention also relates to processes for the manufacture of compounds of formula II.

Compounds of formula II may be prepared by one of the following processes:

-   (i) Compounds of formula II wherein Ar¹ is different from a mono-,     di- or tri-substituted phenyl group in which the substituent is NO₂,     Ar², Z, R² and n′ having the same meanings as in general formula II,     may be obtained by classical deprotection methods of compounds of     formula IV     -   in which P represents a protecting group, such as COOEt,         tert-butoxycarbonyl or tosyl, or any other known protecting         group suitable for a piperazine, Ar¹, Ar², Z, R² and n′ having         the same meanings as in formula II. For more details concerning         deprotection methods, see “Protective Groups in Organic         Chemistry”, J. F. W. Omie, Plenum Press, London and New York,         1973 and “Protective Groups in Organic Synthesis, Th. W. Greene,         John Wiley & Sons, 1981. -   (ii) Compounds of formula II in which Ar1 is a mono-, di- or     tri-substituted phenyl group in which the substituent is NO₂, Ar²,     Z, R² and n′ having the same meanings as in general formula II, may     be obtained by nitration of compounds of formula II in which Ar1 is     a phenyl group, according to the method described in Lynch B. M.,     Poon L., Can. J. Chem. (1967), 45, 1431.

Compound of formula IV used for the preparation of compound of formula II may be obtained by the following methods:

-   -   when, in formula IV, Z represents O, Ar¹, Ar², Z, n′ and P         having the same meanings as stated above, a compound of formula         V is reacted with an alkylating agent of formula VI according to         the equation     -   wherein Y represents a leaving group such as a halogen atom,         preferably a Chlorine, a Bromine or a Iodine atom, a mesyl, a         tosyl or a trichloroacetamidate group, Ar¹, Ar², R², n′ and P         having the same meanings as in formula IV. When Y represents a         halogen atom, a mesyl or a tosyl group, this reaction is known         per se and is generally carried out in an inert organic solvent,         for example dimethylformamide or tetrahydrofuran, in the         presence of a strong base, such as NaH and in the presence of a         catalyst when Y represents a Chlorine or a Bromine atom, for         example sodium iodide or potassium iodide. More exactly, the         anion of compound of formula V is preformed between 0° C. and         room temperature; after addition of compound of formula VI, the         mixture is stirred between room temperature and 50° C. When Y         represents a trichloroacetamidate group, the O-alkylation of         compound of formula V may be carried out in the presence of a         strong acid such as trifluoromethane-sulfonic acid as described         in patent application WO 97/14671.     -   when in formula IV Z represents S, Ar¹, Ar², Z, n′ and P having         the same meanings as in general formula IV, a compound of         formula XV is reacted with an alkylating agent of formula XV         according to the equation     -   wherein Hal represents a halogen atom, preferably a Bromine         atom, Ar¹, Ar², n′ and P having the same meanings as stated         above. This reaction is generally carried out in an inert         solvent, for example toluene, dimethylformamide, an alcohol or         an ether, in the presence of an organic base, for example         diethylamine or pyrrolidine, or in the presence of an inorganic         base, for example NaH, NaBH₄, sodium hydroxide, sodium methoxide         or potassium hydroxide, between −10 and 50° C.

The starting materials used for the preparation of compounds of formula IV may be prepared according to the following procedures:

-   -   compounds of formula V may be obtained according to four         differents methods:     -   1. the reaction of a piperazine of formula VII with an epoxide         derivative of formula VIII according to the equation         -   in these formulae, Ar¹, n′ and P have the same meanings as             stated above.     -   2. the reduction of compound of formula IX according to the         equation         -   wherein Rv represents a hydrogen atom or an alkyl group,             Ar¹, n′ and P having the same meanings as stated above.         -   Compound IX may be obtained by reaction of compounds of             formula VII with an α-bromo ester of formula X according to             the equation         -   wherein R^(v) represents a hydrogen atom or an alkyl group,             Ar¹, n′ and P having the same meanings as stated above.     -   3. the reaction of a piperazine of formula VII with a heteroaryl         boronic acid of formula XI in presence of glyoxylic acid         according to the equation         -   wherein Ar¹, n′ and P have the same meanings as stated in             formula V (see Petasis N. A. et al., Tetrahedron (1997), 53,             16463-16470).     -   4. when in formula V P is a tosyl group, Ar¹ and n′ having the         same meanings as stated above the reaction of the amine of         formula XII with a disubstituted         N,N-diethyl-4-methylbenzenesulfonamide according to the equation         -   wherein Ar¹ and n′ have the same meanings as stated above             and T is a Chlorine, Bromine or Iodine atom or             (4-methylphenyl)sulfonyloxy or methylsulfonyloxy group. This             reaction may be carried out under the conditions disclosed             in European Patent Application 617 028 A1. Compounds of             formula XII may be obtained by conventional reduction of the             corresponding carboxylic acid.     -   compounds of formula XIV may be obtained by reaction of a         compound of formula XVI with a thioacetate salt, for example         potassium thioacetate, according to the equation     -    wherein Ar¹, n′ and P have the same meanings as stated above.         This reaction is carried out in an inert solvent, for example         toluene, dimethylformamide, an alcohol, ethyl acetate or         dichloromethane between −10° C. and 40° C.

Compounds of formula XVI may be obtained by halogenation of a compound of formula V in presence of thionyl chloride according to the equation

wherein Ar¹, n′ and P have the same meanings as stated above.

The following examples illustrate the present invention without limiting it.

Unless specified otherwise in the examples, characterization of the compounds was performed according to the following methods:

NMR spectra were recorded on a BRUKER AC 250 Fourier Transform NMR Spectrometer fitted with an Aspect 3000 computer and with a 5 mm 1H/13C dual probehead. The compound was studied in DMSO (or CDCl3) solution at the probe temperature of 313 K and at a concentration of 20 mg/ml. The instrument was locked on the deuterium signal of DMSO (or CDCl3). Chemical shifts are given in ppm downfield from TMS taken as internal standard.

Mass spectrometric measurements in LC/MS mode were performed as follows:

HPLC Conditions

Analyses were performed using a WATERS Alliance HPLC system mounted with an INERTSIL CHROMPACK 3 ODS, DP 5 μm, 250×4.6 mm column.

The gradient ran from 100% solvent A (acetonitril, water, TFA (10/90/0.1, v/v/v)) to 100% solvent B (acetonitrile, water, TFA (90/10/0.1, v/v/v)) in 7 min with a hold at 100% B of 4 min. The flow rate was set at 2.5 ml/min and a split of 1/10 was used just before API source. The chromatography was carried out at 30° C.

MS Conditions

Samples were dissolved in acetonitrile/water, 70/30, v/v at the concentration of about 250 μgr/ml. API spectra (+ or −) were performed using a FINNIGAN (San Jose, Calif., USA) LCQ ion trap mass spectrometer. APCI source operated at 450° C. and the capillary heater at 160° C. ESI source operated at 3.5 kV and the capillary heater at 210° C.

Mass spectrometric measurements in EI/DIP mode were performed as follows: samples were vaporized by heating the probe from 50° C. to 250° C. in 5 min. EI (Electron Impact) spectra were recorded using a FINNIGAN (San Jose, Calif., USA) TSQ 700 tandem quadrupole mass spectrometer. The source temperature was set at 150° C.

Specific rotation was recorded on a Perlin-Elmer MC241 polarimeter. The angle of rotation was recorded at 25° C. on 1% solutions in MeOH. For some molecules, the solvent was CH2Cl2 or DMSO, due to solubility problems.

Water content is determined using a Metrohm microcoulometric Karl Fischer titrator.

Chromatographic separations are performed on silicagel 60 Merck, particle size 15-40 μm, reference 1.15111.9025.

Unless specified otherwise in the examples, the compounds are obtained as the free bases. The conversion of these free bases into non-toxic pharmaceutically acceptable salts may proceed according to conventional methods known to those skilled in the art. The following general method are given by way of illustration.

For the formation of hydrochlorides or dihydrochlorides of α-arylethylpiperazine derivatives of formula I, free bases were dissolved in an inert solvent, for example CH₂Cl₂, diisopropylether, and a solution of 1,2 or 3 equivalents of HCl in diethylether was added. The volatile substances were removed and the product was recrystallized, usually, from CH₃CN. The salts could also be obtained directly from acidic hydrolysis in the last step and the solid products might be obtained by lyophilisation. The exact salt composition of the product was determined by elemental analysis. The exact quantity of water was determined by Karl Fischer method.

For the formation of the maleates or dimaleate of α-arylethylpiperazine derivatives of formula I, free bases were dissolved in 2-butanone and 1 or 2 equivalents of maleic acid were added. The solids were filtered and the products recrystallized from CH₃CN. The exact salt composition of the product was determined by elemental analysis. The exact quantity of water was determined by Karl Fischer method.

In the following examples,

-   -   when the molecule contains one asymetric center, NSA and NSB are         individual optical isomers for which absolute configuration has         not been determined;     -   when the molecule contains two asymmetric centers, NSA and NSB         refer to couple of enantiomers of which the absolute         configuration has not been determined; when the absolute         configuration has been determined for one or for the two         asymmetric centers, the first R, S or rac. symbol refers to the         absolute configuration of the Carbon atom which bears Ar1, and         the second R, S or rac. symbol refers to the absolute         configuration of the other asymmetric center.

EXAMPLE 1 Preparation of Compounds of Formula I According to Process (a)

1.1. Preparation of Compounds of Formula V

Method 1.

In a round-bottomed flask fitted with a reflux condenser and a thermometer, 15 g (125 mmoles) of (R)-phenyloxirane, 19.75 g (125 mmoles, 18.3 ml) of ethyl-N-piperazine carboxylate, and 80 ml of ethyl alcohol were introduced. The mixture was heated at reflux for 3 hours. Volatile substances were removed under reduced pressure and the resulting mixture was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/aqueous ammonia 98.5/1.5/0.5 (v/v/v)), affording 8.8 g of (S)-4-(2-Hydroxy-1-phenyl-ethyl)-piperazine-1-carboxylic acid ethyl ester (compound 2) as a colorless oil. Yield: 25%.

The compounds of formula V presented in Table I were prepared according to this method.

TABLE I Compounds of formula V obtained by Method 1. Cpd No. P n′ Ar¹ stereochemistry 1 COOEt 1 phenyl racemic 3 COOEt 1 phenyl R 4 COOEt 1 4-methylphenyl racemic 5 COOEt 1 4-fluorophenyl racemic 6 COOEt 1 1-naphthyl racemic 7 COOEt 1 2-naphthyl racemic

The starting oxiranes used for the preparation of compounds 4 to 7 may be obtained by the method disclosed in Bouha H. et al., Synthetic Communications (1987), 17(5), 503-513.

Method 2.

In a round-bottomed flask fitted with a reflux condenser and a thermometer 62.8 g (397 mmoles) of ethyl N-piperazinecarboxylate, 60.3 g (596 mmoles) of triethylamine, and 1980 ml of methyl alcohol were introduced; 109.3 g (477 mmoles) of methyl-1-bromo-1-phenylacetate were added dropwise to this mixture. The solution was heated at reflux for 24 hours. The volatile substances were removed under reduced pressure; 700 ml of methylene chloride were added to the residue; the mixture was filtered and the organic phase was washed with water and then with brine, dried over magnesium sulfate, and concentrated under reduced pressure, affording 114 g of 4-(Methoxycarbonyl-phenyl-methyl)-piperazine-1-carboxylic acid ethyl ester as an oil. Yield: 94%.

In a round-bottomed flask fitted in a reflux condenser and a thermometer 57.0 g (186 mmoles) of 4-(Methoxycarbonyl-phenyl-methyl)-piperazine-1-carboxylic acid ethyl ester obtained above and 660 ml of THF were introduced under nitrogen. The solution was cooled to −20° C., and 7.0 g (185 mmoles) of lithium aluminium hydride were added portion-wise. The reaction mixture was stirred at −15° C. for 45 min, cooled to −35° C.; 7 ml of a 15% (w/w) solution of sodium hydroxide in water and 21 ml of water were successively added to the reaction mixture. The mixture was filtered, the precipitate was washed with THF, and the combined organic phases were concentrated under reduced pressure. The residue was dissolved in methylene chloride (1 l) and the solution was washed with water and then brine. The organic phase was dried over magnesium sulfate and concentrated under reduced pressure, affording 47.2 g of an oil. This oil was purified by chromatography on silica gel (eluent: methylene chloride-aqueous ammonia 98.5/1.5/0.15 (v/v/v)) affording 34.6 g of 4-(2-hydroxy-1-phenyl-ethyl)-piperazine-1-carboxylic acid ethyl ester (compound 1) as a yellow oil. Yield: 67%.

The compounds of formula V identified in Table II were prepared according to this method.

TABLE II Compounds of formula V obtained by Method 2. stereo- Cpd No. P n′ Ar¹ chemistry 8 Boc 1 phenyl racemic 9 COOEt 1 3,5-(bistrifluoromethyl)-phenyl racemic 10 COOEt 1 4-bromophenyl racemic 11 COOEt 1 3-chlorophenyl racemic 12 COOEt 1 3,4-dichlorophenyl racemic 15 COOEt 1 2,3-difluorophenyl racemic 16 COOEt 1 3,4,5-trifluorophenyl racemic 17 Boc 2 phenyl racemic

The starting alkylating agents used for the preparation of compounds 9 to 12 and 16 may be obtained by the method described in Carini D. J. et al., J. Med. Chem. (1990), 33, 1330-1336.

The enantiomers of compound 12, compound 13 (NSA) and compound 14 (NSB), were obtained by resolution by chiral chromatography (Chiralcel OD, 226 nm, 23° C. Eluent: iPrOH 17.5%, benzine 82.5%+DEA 0.1%), compound 13 being the compound that elutes the fastest.

Method 3.

Following the procedure described in Petasis N. A. et al. in Tetrahedron (1997), 53, 16463-16470, ethyl-N-piperazine carboxylate was reacted with 3-isopropylphenyl-boron dihydroxide in the presence of glycolaldehyde to provide 4-[2-hydroxy-1-(3-isopropyl-phenyl)-ethyl]-piperazine-1-carboxylic acid ethyl ester (compound 18). The compounds listed in Table III were obtained by the same method.

TABLE III Compounds of formula V obtained by Method 3. Cpd No. P n′ Ar¹ stereo-chemistry 19 COOEt 1 4-methoxyphenyl racemic 20 COOEt 1 thiophen-2-yl racemic 21 COOEt 1 thiophen-3-yl racemic 22 COOEt 1 furan-2-yl racemic 23 COOEt 1 benzo[c]thiophen-1-yl racemic 24 COOEt 1 isobenzofuran-1-yl racemic

Method 4.

2-Phenyl-2-[4-(toluene-4-sulfonyl)-piperazin-1-yl]-ethanol (compound 25) was obtained from 2-phenylethan-1-olamine and N,N-bis(chloroethyl)-4-methylbenzenesulfonamide following the method described in European Patent Application 617 028 A1. When starting from (S) or (R) 2-phenylethan-1-olamine, the corresponding (S) or (R) 2-Phenyl-2-[4-(toluene-4-sulfonyl)-piperazin-1-yl]-ethanol (compounds 26 and 27, respectively) were obtained.

1.2. Preparation of Compounds of Formula IV

1.2.1. Preparation of compounds of formula IV wherein Z is O.

In a round-bottomed flask fitted with a reflux condenser and a thermometer 8.8 g (32 mmoles) of (S)-4-(2-Hydroxy-1-phenyl-ethyl)-piperazine-1-carboxylic acid ethyl ester (compound 2 prepared at example 1.1) and 50 ml of THF were introduced. The solution was cooled to 0° C. and 1.5 g of sodium hydride (47 mmoles, 78% in parafin) were added portionwise. The solution was allowed to reach room temperature and was stirred for 30 minutes. The solution was cooled again to 0° C., and a solution of 8.5 g (32 mmoles) of 3,5-bis-(trifluoromethyl)-benzyl chloride in 20 ml of THF was added dropwise. Sodium iodide (4.7 g, 32 mmoles) was added to the mixture, which was then stirred at room temperature for 24 hours. The mixture was then cooled to 0° C. and the reaction was quenched with 20 ml of aqueous ammonium chloride. The volatile substances were removed under reduced pressure, 100 ml of water were added, and the pH was adjusted to 11 by addition of aqueous sodium hydroxide. The mixture was extracted with diethyl ether, the organic phase was dried over magnesium sulfate, and concentrated under reduced pressure, affording 15.4 g of an oil. This oil was purified by chromatography on silica gel (eluent: methylene chloride-methanol-aqueous ammonia 99/1/0.5 (v/v/v)), affording 9.5 g of (S)-4-[2-(3,5-bis-[trifluoromethyl]-benzyloxy)-1-phenyl-ethyl]-piperazine-1-carboxylic acid ethyl ester (compound 30) as a yellow oil. Yield: 60%.

The compounds listed in Table IV were obtained by the same method. When R³ represents CH₃, the starting alkylating agents used according to this method may be obtained by the method disclosed in Owens A. P. et al., Bio. Med. Chem. Lett. (1995), 5, 2761-2766.

TABLE IV Preparation of compounds of formula IV wherein Z is O stereo- starting Cpd No. P n′ R² Ar¹ Ar² chemistry cpd No. 28 Boc 1 H phenyl 3,5-bis(trifluoromethyl)phenyl racemic 8 29 COOEt 1 H phenyl 3,5-bis(trifluoromethyl)phenyl racemic 1 31 COOEt 1 H phenyl 3,5-bis(trifluoromethyl)phenyl R 3 32 Tos 1 H phenyl 3,5-bis(trifluoromethyl)phenyl racemic 25 33 Tos 1 H phenyl 3,5-bis(trifluoromethyl)phenyl S 26 34 Tos 1 H phenyl 3,5-bis(trifluoromethyl)phenyl R 27 35 COOEt 1 H 4-methylphenyl 3,5-bis(trifluoromethyl)phenyl racemic 4 36 COOEt 1 H 3-isopropylphenyl 3,5-bis(trifluoromethyl)phenyl racemic 18 37 COOEt 1 H 4-methoxyphenyl 3,5-bis(trifluoromethyl)phenyl racemic 19 38 COOEt 1 H 3-chlorophenyl 3,5-bis(trifluoromethyl)phenyl racemic 11 39 COOEt 1 H 4-bromophenyl 3,5-bis(trifluoromethyl)phenyl racemic 10 40 COOEt 1 H 4-fluorophenyl 3,5-bis(trifluoromethyl)phenyl racemic 5 41 COOEt 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl racemic 12 42 COOEt 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl NSA 13 43 COOEt 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl NSB 14 44 COOEt 1 H 2,3-difluorophenyl 3,5-bis(trifluoromethyl)phenyl racemic 15 45 COOEt 1 H 3,4,5-trifluorophenyl 3,5-bis(trifluoromethyl)phenyl racemic 16 46 COOEt 1 H 1-naphthyl 3,5-bis(trifluoromethyl)phenyl racemic 6 47 COOEt 1 H 2-naphthyl 3,5-bis(trifluoromethyl)phenyl racemic 7 48 COOEt 1 H thiophen-2-yl 3,5-bis(trifluoromethyl)phenyl racemic 20 49 COOEt 1 H thiophen-3-yl 3,5-bis(trifluoromethyl)phenyl racemic 21 50 COOEt 1 H furan-2-yl 3,5-bis(trifluoromethyl)phenyl racemic 22 51 COOEt 1 H benzo[c]thiophen-1-yl 3,5-bis(trifluoromethyl)phenyl racemic 23 52 COOEt 1 H isobenzofuran-1-yl 3,5-bis(trifluoromethyl)phenyl racemic 24 53 COOEt 1 H phenyl 2,4-bis(trifluoromethyl)phenyl racemic 1 54 COOEt 1 H phenyl 3,5-dimethylphenyl racemic 1 55 COOEt 1 H phenyl 3,5-bis(tert-butyl)phenyl racemic 1 56 COOEt 1 H phenyl 2-methoxyphenyl racemic 1 57 COOEt 1 H phenyl 3-isopropoxyphenyl racemic 1 58 COOEt 1 H phenyl 2-trifluoromethoxyphenyl racemic 1 59 COOEt 1 H phenyl 3,4,5-trimethoxyphenyl racemic 1 60 Tos 1 H phenyl 3-chlorophenyl racemic 25 61 COOEt 1 H phenyl 3,5-dichlorophenyl racemic 1 62 Tos 1 H phenyl 3,5-dichlorophenyl S 26 63 Tos 1 H phenyl 3,5-dichlorophenyl R 27 64 COOEt 1 H phenyl 3,4-dichlorophenyl racemic 1 65 Tos 1 H phenyl 3,5-dibromophenyl racemic 25 66 Tos 1 H phenyl 3,5-difluorophenyl racemic 25 67 Boc 1 H phenyl 3-bromo-5-iodophenyl racemic 8 68 Boc 1 H phenyl 3,5-dichloro-4-methoxyphenyl racemic 8 69 COOEt 1 H 3,5-bis(trifluoromethyl)phenyl phenyl racemic 9 70 COOEt 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl racemic 1 73 Tos 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl racemic 25 76 Tos 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl S, rac. 26 79 Tos 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl R, rac. 27 82 Boc 2 H phenyl 3,5-bis(trifluoromethyl)phenyl racemic 17

The following racemic mixtures were resolved into their isomers by chromatographic separation on silica gel 60 or on chiral stationary phases:

-   -   compound 70: stationary phase: silica gel 60; eluent: CH₂Cl₂;         the individual enantiomers so-obtained will be referred to as         compounds 71 (NSA) and 72 (NSB), 71 being the compound that         elutes the fastest under the given conditions;     -   compound 73: stationary phase: silica gel 60; eluent: benzine         40%, CH₂Cl₂ 60%; the individual isomers so-obtained will be         referred to as compounds 74 (NSA) and 75 (NSB), 74 being the         compound that elutes the fastest.     -   compound 76: stationary phase: CHIRALPAK AD, detection at 226         nm; temperature 20° C.; eluent: ethanol 5%, benzine 95%,         diethylamine 0.1%; the individual diastereoisomers so-obtained         will be referred to as compounds 77 (S,R) and 78 (S,S), 77 being         the compound that elutes the fastest.     -   compound 79: stationary phase: silica gel 60; eluent: benzine         40%, CH₂Cl₂ 60%; the individual diastereoisomers so-obtained         will be referred to as compounds 80 (R,R) and 81 (R,S), 80 being         the compound that elutes the slowest.

1.2.2. Preparation of compounds of formula IV wherein Z is S.

a. In a round-bottomed flask fitted with a reflux condenser and a thermometer 6.3 g (17.5 mmoles) of 2-phenyl-2-[4-(toluene-4-sulfonyl)-piperazin-1-yl]-ethanol (compound 25 prepared at example 1.1) and 20 ml of methanol are introduced. An excess of 3 N methanolic HCl is added dropwise, the volatile substances are removed under reduced pressure, affording the dihydrochloride salt of 2-phenyl-2-[4-(toluene-4-sulfonyl)-piperazin-1-yl]-ethanol. To the salt are added 250 ml of CHCl₃, the mixture is cooled to 0° C., and 4.7 g (39.5 mmoles) of SOCl₂ are added dropwise. After completion of the addition, the mixture is heated at reflux for 3 hours. The volatile substances are removed under reduced pressure, affording crude 1-(2-chloro-1-phenyl-ethyl)-4-(toluene-4-sulfonyl)-piperazine as an oil. Ethyl alcohol (300 ml), 2.5 g (22.2 mmoles) of potassium thioacetate, and 3.07 g (22.2 mmoles) of potassium carbonate are then added to this crude product. The mixture is stirred for 16 hours, and the volatile substances are removed under reduced pressure. 150 ml of ether and 150 ml of water are added to the residue, and the mixture is filtered, affording the crude thioacetic acid S-{2-phenyl-2-[4-(toluene-4-sulfonyl)-piperazin-1-yl]-ethyl}ester (compound 83) as a white solid. The aqueous phase is extracted three times with methylene chloride. The solid is dissolved in methylene chloride, the methylene chloride solutions are combined and washed with brine, dried over magnesium sulfate and concentrated under reduced pressure, affording 4.32 gr of compound 83 as a white solid. Yield: 59%.

b. In a round-bottomed flask fitted with a reflux condenser and a thermometer 2.76 g (6.6 mmoles) of thioacetate 83 and 250 ml of degassed methyl alcohol are introduced. The mixture is cooled to 0° C. and 356 mg (6.6 mmoles) of sodium methylate are added. The mixture is stirred under argon for one hour at 0° C., and 1.9 g (7.26 mmoles) of 3,5-bis-trifluoromethyl-benzyl bromide are added. The mixture is stirred for 48 hours, volatile substances are removed under reduced pressure, and 100 ml of water are added. The aqueous phase is extracted three times with methylene chloride, the combined organic phases are washed with brine and dried over magnesium sulfate. Volatile substances are removed under reduced pressure, affording 4.54 g of crude 1-[2-(3,5-bis-trifluoromethyl-benzylsulfanyl)-1-phenyl-ethyl]-4-(toluene-4-sulfonyl)-piperazine (compound 84) as a colorless oil. This oil was purified by chromatography on silica gel (eluent: methylene chloride-hexane 65/35 (v/v)), affording 3.26 g of compound 84 as a colorless oil. Yield: 82%.

1-[2-(3,5-Dimethyl-benzylsulfanyl)-1-phenyl-ethyl]-4-(toluene-4-sulfonyl)-piperazine (compound 85) was obtained by the same method.

1.3. Preparation of Compounds of Formula II

1.3.1. Preparation of compounds of formula II wherein Ar1 is not a mono-, di- or tri-substituted phenyl group in which the substituent is NO₂.

The compounds of formula II summarized in Table V are obtained by classical deprotection methods of corresponding compounds of formula IV. For more details concerning deprotection methods, see “Protective Groups in Organic Chemistry”, J. F. W. Omie, Plenum Press, London and New York, 1973 and “Protective Groups in Organic Synthesis, Th. W. Greene, John Wiley & Sons, 1981.

Physico-chemical properties of the compounds of formula II prepared according to this method are given in Table Va below. When the compounds of formula II are in the form of non toxic pharmaceutically acceptable salts, they are obtained by the general method stated above.

TABLE V Preparation of compounds of formula II by deprotection of compounds of formula IV Stereo- Starting cpd Cpd No. n′ R2 Ar¹ Ar² Z chemistry No. 86 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O racemic 28, 29 or 32 87 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O S 30 or 33 88 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O R 31 or 34 89 1 H 4-methylphenyl 3,5-bis(trifluoromethyl)phenyl O racemic 35 90 1 H 3-isopropylphenyl 3,5-bis(trifluoromethyl)phenyl O racemic 36 91 1 H 4-methoxyphenyl 3,5-bis(trifluoromethyl)phenyl O racemic 37 92 1 H 3-chlorophenyl 3,5-bis(trifluoromethyl)phenyl O racemic 38 93 1 H 4-bromophenyl 3,5-bis(trifluoromethyl)phenyl O racemic 39 94 1 H 4-fluorophenyl 3,5-bis(trifluoromethyl)phenyl O racemic 40 95 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl O racemic 41 96 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl O NSA 42 97 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl O NSB 43 98 1 H 2,3-difluorophenyl 3,5-bis(trifluoromethyl)phenyl O racemic 44 99 1 H 3,4,5-trifluorophenyl 3,5-bis(trifluoromethyl)phenyl O racemic 45 100 1 H 1-naphthyl 3,5-bis(trifluoromethyl)phenyl O racemic 46 101 1 H 2-naphthyl 3,5-bis(trifluoromethyl)phenyl O racemic 47 102 1 H thiophen-2-yl 3,5-bis(trifluoromethyl)phenyl O racemic 48 103 1 H thiophen-3-yl 3,5-bis(trifluoromethyl)phenyl O racemic 49 104 1 H furan-2-yl 3,5-bis(trifluoromethyl)phenyl O racemic 50 105 1 H benzo[c]thiophen-1-yl 3,5-bis(trifluoromethyl)phenyl O racemic 51 106 1 H isobenzofuran-1-yl 3,5-bis(trifluoromethyl)phenyl O racemic 52 107 1 H phenyl 2,4-bis(trifluoromethyl)phenyl O racemic 53 108 1 H phenyl 3,5-dimethylphenyl O racemic 54 109 1 H phenyl 3,5-bis(tert-butyl)phenyl O racemic 55 110 1 H phenyl 2-methoxyphenyl O racemic 56 111 1 H phenyl 3-isopropoxyphenyl O racemic 57 112 1 H phenyl 2-trifluoromethoxyphenyl O racemic 58 113 1 H phenyl 3,4,5-trimethoxyphenyl O racemic 59 114 1 H phenyl 3-chlorophenyl O racemic 60 115 1 H phenyl 3,5-dichlorophenyl O racemic 61 116 1 H phenyl 3,5-dichlorophenyl O S 62 117 1 H phenyl 3,5-dichlorophenyl O R 63 118 1 H phenyl 3,4-dichlorophenyl O racemic 64 119 1 H phenyl 3,5-dibromophenyl O racemic 65 120 1 H phenyl 3,5-difluorophenyl O racemic 66 121 1 H phenyl 3-bromo-5-iodophenyl O racemic 67 122 1 H phenyl 3,5-dichloro-4-methoxyphenyl O racemic 68 123 1 H 3,5-bis(trifluoromethyl)phenyl phenyl O racemic 69 124 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl O NSA 71 125 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl O NSB 72 or 75 126 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl O S, R 77 127 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl O S, S 78 128 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl O R, R 80 129 1 CH3 phenyl 3,5-bis(trifluoromethyl)phenyl O R, S 81 130 2 H phenyl 3,5-bis(trifluoromethyl)phenyl O racemic 82 131 1 H phenyl 3,5-bis(trifluoromethyl)phenyl S racemic 84 132 1 H phenyl 3,5-dimethylphenyl S racemic 85

TABLE Va Physico-chemical properties of compounds of formula II. Cpd No. Free base/salt Physico-chemical properties 86 ¹H-NMR (DMSO): 7.94 (s, 1H), 7.85 (s, 2H), 7.4-7.2 (m, 5H), 4.65 (s, 2H), 3.92 (dd, 1H), 3.78 (dd, 1H), 3.59 (t, 1H), 2.75-2.55 (m, 4H), 2.45-2.2 (m, 4H). Mass: (LC/MS APCI+): 433 (MH+). 90 2 HCl.¾ H₂O ¹H-NMR (DMSO): 8.02 (s, 1H), 7.94 (s, 2H), 7.37 (s, 1H), 7.34 (m, 2H), 7.31 (t, 1H), 4.74 (s, 2H), 4.59 (m, 1H), 4.32 (m, 1H), 4.05 (m, 1H), 3.41 (m, 8H), 2.89 (m, 1H), 1.21 (d, 6H). Mass: (LC/MS APCI+): 475 (MH+). 91 2 HCl.1 H₂O ¹H-NMR (DMSO): 7.91 (s, 1H), 7.84 (s, 2H), 7.4 (d, 2H), 6.95 (d, 2H), 4.7 (dd, 2H), 4.47 (t, 1H), 4.1-3.9 (m, 2H), 3.73 (s, 3H), 3.4-3.2 (m, 6H), 3.2-3.05 (m, 2H). Mass: (LC/MS APCI+): 463 (MH+). 92 2 maleate ¹H-NMR (DMSO): 7.9 (s, 1H), 7.75 (s, 2H), 7.35-7.2 (m, 4H), 6.18 (s, 4H), 4.6 (s, 2H), 4.0-3.65 (m, 3H), 3.0 (m, 4H), 2.6 (m, 4H). Mass: (LC/MS APCI+): 467/469 (MH+). 94 2 HCl.⅔ H₂O ¹H-NMR (DMSO): 7.91 (s, 1H), 7.81 (s, 2H), 7.52 (dd, 2H), 7.2 (d + d, 2H), 4.75 (s, 2H), 4.44 (t, 1H), 4.1-3.95 (m, 2H), 3.4-3.2 (m, 6H), 3.2-3.05 (m, 2H). Mass: (LC/MS APCI+): 451 (MH+). 95 2 HCl ¹H-NMR (DMSO): 7.91 (s, 1H), 7.76 (s, 2H), 7.64 (d, 1H), 7.58 (d, 1H), 7.38 (dd, 1H), 4.65 (s, 2H), 4.08 (t, 1H), 3.91 (d, 2H), 3.25-3.15 (m, 4H), 3.0-2.7 (m, 4H). Mass: (LC/MS APCI+): 501/503/505 (MH+). 98 1 maleate ¹H-NMR (DMSO): 8.2 (s, 2H), 8.0 (s, 1H), 7.8 (s, 2H), 7.3 (m, 1H), 7.2 (m, 2H), 6.0 (s, 2H), 4.7 (m, 2H), 4.2 (m, 1H), 4.0 (m, 1H), 3.9 (m, 1H), 2.0-2.5 (m, 8H). Mass: (LC/MS APCI+): 469 (MH+). 100 2 HCl ¹H-NMR (DMSO): 8.21 (d, 1H), 7.92 (d, 2H), 7.83 (s, 1H), 7.7 (d + s, 3H), 7.6-7.4 (m, 3H), 5.05 (t, 1H), 4.64 (s, 2H), 4.15-3.95 (m, 2H), 3.85-3.65 (m, 6H), 3.15-2.95 (m, 2H). Mass: (EI/DIP): 482 (M+). 101 ¹H-NMR (CDCl3): 7.82 (dd, 3H), 7.74 (s, 2H), 7.65 (s, 2H), 7.45 (dd, 3H), 4.57 (s, 2H), 3.95 (dd, 1H), 3.85 (dd, 1H), 3.72 (t, 1H), 2.95 (m, 4H), 2.6-2.4 (m, 4H). Mass: (LC/MS APCI+): 483 (MH+). 107 ¹H-NMR (DMSO): 7.97 (d, 1H), 7.92 (s, 1H), 7.75 (d, 1H), 7.35-7.15 (m, 5H), 4.7 (s, 2H), 3.92 (dd, 1H), 3.78 (dd, 1H), 3.57 (t, 1H), 2.75-2.55 (m, 4H), 2.45-2.2 (m, 4H). Mass: (LC/MS APCI+): 433 (MH+). 108 ¹H-NMR (DMSO): 7.35-7.15 (m, 5H), 6.87 (s, 1H), 6.79 (s, 2H), 4.43 (s, 2H), 3.78 (dd, 1H), 3.66 (dd, 1H), 3.53 (t, 1H), 2.75-2.55 (m, 4H), 2.45-2.2 (m, 4H), 2.22 (s, 6H). Mass: (LC/MS APCI+): 325 (MH+). 109 2 maleate ¹H-NMR (DMSO): 7.29 (m, 5H), 7.24 (s, 1H), 6.99 (s, 2H), 6.17 (s, 2H), 4.40 (m, 1H), 3.95-3.6 (m, 4H), 3.04 (m, 4H), 2.65-2.5 (m, 4H), 1.19 (s, 9H). Mass: (LC/MS APCI+): 409 (MH+). 110 ¹H-NMR (DMSO): 7.35-7.15 (m, 7H), 6.95 (d, 1H), 6.88 (t, 1H), 4.44 (s, 2H), 3.9-3.6 (m, 2H), 3.75 (s, 1H), 3.55 (t, 1H), 3.41 (s, 3H), 2.75-2.55 (m, 4H), 2.45-2.2 (m, 4H). Mass: (LC/MS APCI+): 327 (MH+). 112 ¹H-NMR (DMSO): 7.45-7.15 (m, 9H), 4.55 (s, 2H), 3.85 (dd, 1H), 3.75 (dd, 1H), 3.55 (t, 1H), 2.75-2.55 (m, 4H), 2.45-2.2 (m, 4H). Mass: (LC/MS APCI+): 381 (MH+). 113 ¹H-NMR (DMSO): 7.35-7.2 (m, 5H), 6.51 (d, 2H), 4.36 (d, 2H), 3.9-3.5 (m, 3H), 3.71 (s, 6H), 3.64 (s, 3H), 3.0-2.4 (m, 8H). Mass: (LC/MS APCI+): 387 (MH+). 114 2 HCl ¹H-NMR (DMSO): 7.4-7.25 (m, 9H), 4.45 (s, 2H), 3.85 (m, 1H), 3.8-3.55 (m, 2H), 3.7-3.1 (m, 8H). Mass: (LC/MS APCI): 331/333 (MH+). 115 2 HCl ¹H-NMR (DMSO): 7.55-7.4 (m, 5H), 7.4 (s, 1H), 7.25 (s, 2H), 4.53 (dd, 2H), 4.45 (t, 1H), 4.1-3.8 (m, 2H), 3.4-3.2 (m, 6H), 3.2-3.0 (m, 2H). Mass: (LC/MS APCI+): 365/367/369 (MH+). 118 ¹H-NMR (DMSO): 7.55 (d, 1H), 7.4 (d, 1H), 7.4-7.15 (m, 6H), 4.45 (s, 2H), 3.85 (dd, 1H), 3.73 (dd, 1H), 3.55 (t, 1H), 2.75-2.55 (m, 4H), 2.45-2.2 (m, 4H). Mass: (LC/MS APCI+): 365/367/369 (MH+). 119 2 HCl ¹H-NMR (DMSO): 7.65 (s, 1H), 7.4 (m, 6H), 4.52 (s, 2H), 4.41 (t, 1H), 4.1-3.9 (m, 2H), 3.5-3.2 (m, 6H), 3.2-3.0 (m, 2H). Mass: (LC/MS APCI): 453/455/457 (MH+). 120 2 HCl ¹H-NMR (DMSO): 7.65 (m, 1H), 7.45 (m, 2H), 7.2-7.0 (m, 5H), 4.7-4.5 (m, 1H), 4.6 (s, 2H), 4.3 (m, 1H), 4.0 (m, 1H), 3.6-3.1 (m, 8H). Mass: (LC/MS APCI): 333 (MH+). 121 1 maleate ¹H-NMR (DMSO): 7.8 (s, 1H), 7.6 (s, 1H), 7.4 (s, 1H), 7.3 (m, 5H), 6.1 (s, 2H), 4.5 (s, 2H), 3.8 (m, 3H), 2.6-3.0 (m, 8H). Mass: (LC/MS APCI): 501/503 (MH+). 122 2 HCl ¹H-NMR (DMSO): 7.5-7.4 (m, 5H), 7.3 (s, 2H), 4.47 (s, 2H), 4.4 (t, 1H), 4.1-3.85 (m, 2H), 3.75 (s, 3H), 3.35-3.2 (m, 6H), 3.1 (m, 2H). Mass: (LC/MS APCI+): 395/397/399 (MH+). 130 ¹H-NMR (CDCl3): 7.78 (s, 1H), 7.68 (s, 2H), 7.29 (m, 5H), 4.60 (s, 2H), 4.1-3.9 (m, 2H), 3.85 (m, 1H), 3.30 (m, 2H), 3.12 (m, 2H), 3.03 (m, 2H), 2.87 (m, 4H), 2.05 (m, 2H). Mass: (LC/MS APCI+): 447 (MH+). 131 2 HCl.{fraction (3/2)} H₂O ¹H-NMR (DMSO): 7.75 (s, 1H), 7.65 (s, 2H), 7.2-7.1 (m, 5H), 4.2 (t, 1H), 4.1-3.8 (dd, 2H), 3.3 (m, 2H), 3.2 (m, 4H), 3.1 (m, 4H). Mass: (LC/MS ESI+): 449 (MH+). 132 2 HCl.{fraction (3/2)} H₂O ¹H-NMR (DMSO): 7.35 (m, 5H), 6.82 (s, 1H), 6.74 (s, 2H), 4.15 (t, 1H), 3.54 (s, 2H), 3.45-3.0 (m, 10H), 2.16 (s, 6H). Mass: (LC/MS ESI+): 341 (MH+).

1.3.2. Preparation of compounds of formula II wherein Ar¹ is a mono-, di- or tri-substituted phenyl group in which the substituent is NO₂.

1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2-nitro-phenyl)-ethyl]-piperazine (compound 133) was obtained by nitration of 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazine (compound 86 prepared at example 1.3.1 above) according to the method described in Lynch B. M., Poon L., Can. J. Chem. (1967), 45, 1431.

1.4. Preparation of Compounds of Formula I

1.4.1. Preparation of compounds of formula I according to process (a.1).

In a round-bottomed flask fitted with a reflux condenser and a thermometer 7.5 g (17 mmoles) of 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazine (compound 86 prepared at example 1.3.1 above), 60 ml of DMF and 7.2 g (52 mmoles) of potassium carbonate were introduced. The resulting mixture was cooled to 5° C., and a solution of 5 g (31 mmoles) of 5-bromo-valeronitrile in 10 ml of DMF was added dropwise. The reaction mixture was stirred at 5° C. for 5 hours, and volatile substances were removed under reduced pressure. Methylene chloride (50 ml) was added, the organic phase was washed twice with water, dried over magnesium sulfate, and concentrated under reduced pressure, affording 11.3 g of an oil. This oil was purified by chromatography on silica gel (eluent: methylene chloride-methanol-aqueous ammonia 98.5/1.5/0.15 (v/v/v)), affording 7.2 g of {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 134) as an oil. Yield: 80%.

The compounds listed in Table VI were obtained by this method.

Physico-chemical properties of the compounds of formula I prepared according to this method are given in Table VIa below. When the compounds of formula I are in the form of non toxic pharmaceutically acceptable salts, they are obtained by the general methods given above.

The following racemic mixtures were resolved into their individual enantiomers by chromatography using a chiral stationary phase:

-   -   compound 175: stationary phase: CHIRALPAK AD, detection at 226         nm; temperature 30° C.; eluent: ethanol 10%, benzine 90%,         diethylamine 0.1%; the individual isomers so-obtained will be         referred to as compounds 176 (NSA) and 177 (NSB), 176 being the         compound that elutes the fastest;     -   compound 181: stationary phase: CHIRALCEL OJ, detection at 226         nm; temperature 30° C.; eluent: isopropanol 5%, benzine 95%,         diethylamine 0.1%; the individual isomers so-obtained will be         referred to as compounds 182 (NSA) and 183 (NSB), 182 being the         compound that elutes the fastest;     -   compound 214: stationary phase: CHIRALPAK AS, detection at 226         nm; temperature 30° C.; eluent: ethanol 10%, benzine 90%,         diethylamine 0.1%; the individual isomers so-obtained will be         referred to as compounds 215 (S,R) and 218 (R,S), 215 being the         compound that elutes the slowest;     -   compound 224: stationary phase: CHIRALCEL OJ, detection at 226         nm; temperature: room temperature; eluent: ethanol 5%, benzine         95%, diethylamine 0.1%; the individual isomers so-obtained will         be referred to as compounds 225 (NSA) and 226 (NSB), 225 being         the compound that elutes the fastest.

TABLE VI Compound of formula I by process (a.1) Cpd Stereo- Starting No. chemistry n′ R2 Ar¹ Ar² Z W cpd No. 134 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 86 135 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)CH₂— 86 136 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O iPrO(CO)CH₂— 87 137 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O tBuO(CO)CH₂— 87 138 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)(CH₂)₃— 86 139 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)(CH₂)₄— 86 140 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)(CH₂)₄— 86 141 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)(CH₂)₅— 86 142 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O ^(i)PrO(CO)(CH₂)₅— 86 143 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 86 144 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 87 145 R 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 88 146 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)(CH₂)₂— 87 147 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂O(CH₂)₂— 86 148 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂O(CH₂)₂— 87 149 R 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂O(CH₂)₂— 88 150 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)(CH₂)₅— 86 151 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₃— 86 152 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₄— 86 153 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₄— 87 154 R 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₄— 88 155 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O NC—CH₂O(CH₂)₂— 86 156 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₅— 86 157 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O HO(CH₂)₂— 86 158 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O HO(CH₂)₂O(CH₂)₂— 87 159 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O HO₃S(CH₂)₂— 86 160 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O HO₃S(CH₂)₃— 86 161 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 2-(4-thiomorpholino 1,1-dioxide)ethyl 86 162 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 2-(N-morpholino)ethyl 86 163 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O (EtO)₂(PO)(CH₂)₂— 86 164 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O (EtO)₂(PO)(CH₂)₂— 87 165 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 2-(EtO(CO))—C₆H₄—CH₂— 86 166 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 3-(MeO(CO))—C₆H₄—CH₂— 86 167 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 4-(MeO(CO))—C₆H₄—CH₂— 87 168 S, NS 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O C₆H₅CH(COOMe)— 87 169 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O C₆H₅CH(OH)(CH₂)₂— 86 170 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 2-pyridinyl-CH₂— 86 171 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O N-phthalimidyl-(CH₂)₂— 86 172 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 3,4,5-trimethoxyphenyl-methyl 86 173 S 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 3,4,5-trimethoxyphenyl-methyl 87 174 R 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 3,4,5-trimethoxyphenyl-methyl 88 175 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 3,4,5-trimethoxyphenyl-methoxy-2- 86 ethyl- 178 racemic 1 H 4-methylphenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)CH₂— 89 179 racemic 1 H 3-isopropylphenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)CH₂— 90 180 racemic 1 H 4-methoxyphenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)CH₂— 91 181 racemic 1 H 3-chlorophenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 92 184 racemic 1 H 4-bromophenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 93 185 racemic 1 H 4-fluorophenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₄— 94 186 NSA 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)CH₂— 96 187 NSB 1 H 3,4-dichlorophenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)CH₂— 97 188 racemic 1 H 2,3-difluorophenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 98 189 racemic 1 H 3,4,5-trifluorophenyl 3,5-bis(trifluoromethyl)phenyl O EtO(CO)CH₂— 99 190 racemic 1 H 2-nitrophenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 134 191 racemic 1 H 1-naphthyl 3,5-bis(trifluoromethyl)phenyl O H2N(CO)CH₂— 100 192 racemic 1 H thiophen-2-yl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 102 193 racemic 1 H thiophen-3-yl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 103 194 racemic 1 H furan-2-yl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 104 195 racemic 1 H benzo[c]thiophen-1-yl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 105 196 racemic 1 H isobenzofuran-1-yl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 106 197 racemic 1 H phenyl 3,5-dimethylphenyl O MeO(CO)CH₂— 108 198 racemic 1 H phenyl 2-methoxyphenyl O MeO(CO)CH₂— 110 199 racemic 1 H phenyl 3-isopropoxyphenyl O MeO(CO)CH₂— 111 200 racemic 1 H phenyl 3,4,5-trimethoxyphenyl O H₂N(CO)CH₂— 113 201 racemic 1 H phenyl 3-chlorophenyl O EtO(CO)CH₂— 114 202 racemic 1 H phenyl 3,5-dichlorophenyl O MeO(CO)CH₂— 115 203 S 1 H phenyl 3,5-dichlorophenyl O EtO(CO)CH₂— 116 204 R 1 H phenyl 3,5-dichlorophenyl O EtO(CO)CH₂— 117 205 racemic 1 H phenyl 3,4-dichlorophenyl O MeO(CO)CH₂— 118 206 racemic 1 H phenyl 3,5-dibromophenyl O EtO(CO)CH₂— 119 207 racemic 1 H phenyl 3,5-difluorophenyl O EtO(CO)CH₂— 120 208 racemic 1 H phenyl 3-bromo-5-iodophenyl O MeO(CO)CH₂— 121 209 racemic 1 H 3,5-bis(trifluoromethyl)- phenyl O EtO(CO)CH₂— 123 phenyl 210 NSA 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 124 211 NSB 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 125 212 NSA 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₄— 124 213 NSB 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O NC(CH₂)₄— 125 214 NSB 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 125 215 S, R 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 126 216 S, S 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 127 217 R, R 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 128 218 R, S 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂— 129 219 S, R 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂O(CH₂)₂— 126 220 S, S 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂O(CH₂)₂— 127 221 R, R 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂O(CH₂)₂— 128 222 R, S 1 CH₃ phenyl 3,5-bis(trifluoromethyl)phenyl O H₂N(CO)CH₂O(CH₂)₂— 129 223 racemic 2 H phenyl 3,5-bis(trifluoromethyl)phenyl O MeO(CO)CH₂— 130 224 racemic 2 H phenyl 3,5-bis(trifluoromethyl)phenyl O 3-(MeO(CO))—C₆H₄—CH₂— 130 227 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl O 4-quinolyl 86 228 racemic 1 H phenyl 3,5-bis(trifluoromethyl)phenyl S MeO(CO)CH₂O 131

TABLE VIa Physico-chemical properties of compounds of formula I. Stereo- I chemistry Salt Characteristics 134 racemic 2 HCl ¹H-NMR (DMSO): 7.92 (s, 1H), 7.84 (s, 2H), 7.5-7.3 (m, 5H), 4.69 (dd, 2H), 4.44 (t, 1H), 4.04 (m, 2H), 3.95 (dd, 2H), 3.66 (s, 2H), 6.64 (s, 3H), 3.3-3.15 (m, 2H), 3.1-3.0 (m, 6H). Mass: (LC/MS APCI+): 505 (MH+). 137 S 2 HCl.½ H₂O ¹H-NMR (DMSO): 7.90 (s, 1H), 7.87 (s, 2H), 7.55-7.4 (m, 5H), 4.71 dd, 2H), 4.59 (t, 1H), 4.13 (dd, 1H), 4.02 (dd, 1H), 3.88 (s, 2H), 3.5-3.3 (m, 6H), 3.3-3.1 (m, 2H), 1.4 (s, 9H). Mass: (LC/MS APCI+): 547 (MH+). [α]D = +14.77° (1% CH3OH, 25° C.). 138 racemic 2 maleate ¹H-NMR (DMSO): 7.9 (s, 1H), 7.75 (s, 2H), 7.25 (m, 5H), 6.17 (s, 4H), 4.6 (dd, 2H), 4.1-3.75 (m, 2H), 3.1 (m, 4H), 2.95 (m, 2H), 2.65 (m, 4H), 2.32 (t, 2H), 1.81 (m, 2H), 1.13 (t, 3H). Mass: (LC/MS APCI+): 547 (MH+). 139 racemic 2 maleate ¹H-NMR (DMSO): 7.91 (s, 1H), 7.78 (s, 2H), 7.30 (m, 5H), 6.17 (s, 4H), 4.62 (s, 2H), 4.0-3.8 (m, 3H), 3.77 (s, 3H), 3.3-3.1 (m, 4H), 2.97 (t, 2H), 2.8-2.6 (m, 4H), 2.30 (t, 2H), 1.7-1.5 (m, 4H). Mass: (LC/MS APCI+): 547 (MH+). 141 racemic 2 maleate ¹H-NMR (DMSO): 7.89 (s, 1H), 7.75 (s, 2H), 7.29 (m, 5H), 6.17 (s, 4H), 4.61 (s, 2H), 4.06 (q, 2H), 4.0-3.8 (m, 3H), 3.3-3.1 (m, 4H), 3.01 (t, 2H), 2.8-2.6 (m, 4H), 2.28 (t, 2H), 1.7-1.5 (m, 4H), 1.27 (m, 2H), 1.17 (t, 3H). Mass: (LC/MS APCI+): 575 (MH+). 142 racemic 2 maleate ¹H-NMR (DMSO): 7.89 (s, 1H), 7.76 (s, 2H), 7.29 (m, 5H), 6.17 (s, 4H), 4.82 (m, 1H), 4.61 (s, 2H), 4.05-3.8 (m, 3H), 3.3-3.1 (m, 4H), 2.94 (t, 2H), 2.8-2.6 (m, 4H), 2.20 (t, 2H), 1.7-1.5 (m, 4H), 1.24 (m, 2H), 1.12 (d, 6H) Mass: (LC/MS APCI+): 589 (MH+). 144 S 2 HCl ¹H-NMR (DMSO): 7.91 (s, 1H), 7.85 (s + s, 3H), 7.5-7.3 (m, 6H), 4.7 (s, 2H), 4.25 (t, 1H), 4.0- 3.85 (m, 2H), 3.55 (s, 2H), 3.2-3.1 (m, 6H), 3.05- 2.9 (m, 2H). Mass: (LC/MS APCI+): 490 (MH+). [α]_(D) = +15.43° (1% CH₃OH, 25° C.). 145 R 2 HCl ¹H-NMR (DMSO): 7.91 (s, 1H), 7.85 (s + s, 3H), 7.5-7.3 (m, 6H), 4.7 (dd, 2H), 4.44 (t, 1H), 4.05 (dd, 1H), 3.95 (dd, 1H), 3.73 (s, 2H), 3.4-3.2 (m, 6H), 3.3-3.0 (m, 2H). Mass: (EI/DIP): 489 (M+). [α]_(D) = −17.7° (1% CH₃OH, 25° C.). 147 racemic 2 HCl.½ H₂O ¹H-NMR (DMSO): 7.89 (s, 1H), 7.83 (s, 2H), 7.6 (s, 1H), 7.5-7.3 (m, 5H), 7.15 (s, 1H), 4.69 (dd, 2H), 4.44 (t, 1H), 4.15-3.95 (m, 2H), 3.91 (s, 2H), 3.74 (t, 2H), 3.6-3.4 (m, 4H), 3.4-3.2 (m, 4H), 3.2-3.1 (m, 2H). Mass: (LC/MS ESI+): 534 (MH+). 148 S 2 maleate ½ H₂O ¹H-NMR (DMSO): 7.88 (s, 1H), 7.74 (s, 2H), 7.3 (m, 5H), 6.18 (s, 4H), 4.60 (s, 2H), 4.0-3.7 (m, 7H), 3.88 (s, 2H), 3.69 (t, 2H), 3.2 (m, 6H), 2.7 (m, 2H). Mass: (LC/MS APCI+): 534 (MH+). [α]_(D) = +8.27° (1% CH₃OH, 25° C.). 149 R 2 maleate.½ H₂O ¹H-NMR (DMSO): 7.88 (s, 1H), 7.75 (s, 2H), 7.3 (m, 5H), 6.18 (s, 4H), 4.61 (s, 2H), 4.0-3.7 (m, 7H), 3.88 (s, 2H), 3.68 (t, 2H), 3.2 (m, 6H), 2.7 (m, 2H). Mass: (LC/MS APCI+): 534 (MH+). [α]_(D) = −20° (1% CH₃OH, 25° C.). 150 racemic 2 maleate ¹H-NMR (DMSO): 7.97 (s, 1H), 7.87 (s, 2H), 7.35 (m, 5H), 7.15 (s, 1H), 6.75 (s, 1H), 6.14 (s, 4H), 4.69 (s, 2H), 4.05-3.85 (m, 3H), 3.3-3.1 (m, 4H), 3.04 (t, 2H), 2.8-2.6 (m, 4H), 2.04 (t, 2H), 1.7-1.5 (m, 4H), 1.28 (m, 2H). Mass: (LC/MS APCI): 546 (MH+). 151 racemic 2 maleate ¹H-NMR (DMSO): 7.88 (s, 1H), 7.75 (s, 2H), 7.3 (m, 5H), 6.17 (s, 4H), 4.61 (m, 2H), 4.0-3.8 (m, 3H), 3.1 (m, 4H), 2.95 (m, 2H), 2.7 (m, 4H), 2.5 (m, 2H), 1.85 (m, 2H). Mass: (LC/MS APCI+): 500 (MH+) 152 racemic 2 maleate ¹H-NMR (DMSO): 7.89 (s, 1H), 7.76 (s, 2H), 7.32 (m, 5H), 6.18 (s, 4H), 4.61 (s, 2H), 4.1-3.8 (m, 5H), 3.3-3.2 (m, 4H), 3.01 (t, 2H), 2.8-2.6 (m, 4H), 2.45 (t, 2H), 1.8-1.5 (m, 4H). Mass: (LC/MS APCI): 514 (MH+). 155 racemic 2 maleate ¹H-NMR (DMSO): 7.91 (s, 1H), 7.78 (s, 2H), 7.32 (m, 5H), 6.17 (s, 4H), 4.62 (s, 2H), 4.40 (s, 2H), 4.1-3.8 (m, 5H), 3.19 (t, 2H), 3.2-3.1 (m, 4H), 2.96 (t, 2H), 2.8-2.6 (m, 4H). Mass: (LC/MS APCI): 516 (MH+). 156 racemic 2 maleate ¹H-NMR (DMSO): 7.88 (s, 1H), 7.75 (s, 2H), 7.32 (m, 5H), 6.18 (s, 4H), 4.60 (s, 2H), 4.1-3.8 (m, 3H), 3.3-3.1 (m, 4H), 2.96 (t, 2H), 2.8-2.6 (m, 4H), 2.40 (t, 2H), 1.7-1.5 (m, 4H), 1.27 (m, 2H). Mass: (LC/MS APCI): 528 (MH+) 157 racemic 2 HCl.½ H₂O ¹H-NMR (DMSO): 7.91 (s, 1H), 7.83 (s, 2H), 7.5-7.3 (m, 5H), 4.68 (dd, 2H), 4.36 (t, 1H), 4.1- 3.9 (m, 2H), 3.7 (t, 1H), 3.5-3.3 (m, 4H), 3.3-3.0 (m, 6H). Mass: (LC/MS APCI+): 477 (MH+). 158 S 2 maleate ¹H-NMR (DMSO): 7.89 (s, 1H), 7.76 (s, 2H), 7.3 (m, 5H), 6.17 (s, 4H), 4.61 (dd, 2H), 4.0-3.75 (m, 3H), 3.65 (t, 2H), 3.48 (m, 2H), 3.45 (m, 2H), 3.18 (m, 6H), 2.7 (m, 2H). Mass: (LC/MS APCI+):521 (MH+). [α]_(D) = +9° (1% CH₃OH, 25° C.) 159 racemic 1 H₂O ¹H-NMR (DMSO): 7.76 (s, 1H), 7.64 (s, 2H), 7.35-7.15 (m, 5H), 4.55 (s, 2H), 3.9-3.6 (m, 3H), 3.5 (t, 2H), 3.3 (t, 2H), 3.1-2.6 (m, 8H). Mass: (LC/MS APCI+): 541 (MH+). 160 racemic 2 HCl ¹H-NMR (DMSO): 7.90 (s, 1H), 7.83 (s, 2H), 7.45-7.35 (m, 5H), 4.68 (m, 2H), 4.40 (t, 1H), 4.2-3.8 (m, 2H), 3.5-3.3 (m, 4H), 3.3-3.0 (m, 6H), 2.67 (t, 2H), 1.97 (t, 2H). Mass: (LC/MS APCI+): 555 (MH+). 161 racemic 3 HCl ¹H-NMR (DMSO): 7.95 (s, 1H), 7.89 (s, 2H), 7.6-7.5 (m, 2H), 7.5-7.4 (m, 3H), 4.73 (s, 2H), 4.55 (t, 1H), 4.15 (dd, 1H), 4.05 (dd, 1H), 3.55- 3.4 (m, 4H), 3.4-3.25 (m, 6H), 3.25-3.15 (m, 6H), 3.15-3.05 (m, 4H). Mass: (LC/MS APCI+): 594 (MH+). 162 racemic 3 HCl ¹H-NMR (DMSO): 7.92 (s, 1H), 7.85 (s, 2H), 7.5 (m, 2H), 7.4 (m, 3H), 4.7 (dd, 2H), 4.53 (t, 1H), 4.15-3.85 (m, 2H), 3.85 (t, 4H), 3.4-3.15 (m, 8H), 3.05 (m, 2H), 2.95-2.75 (m, 6H). Mass: (LC/MS APCI+): 546 (MH+). 164 S 2 maleate ¹H-NMR (DMSO): 7.98 (s, 1H), 7.88 (s, 2H), 7.36 (m, 5H), 6.14 (s, 4H), 4.69 (s, 2H), 4.1-3.8 (m, 3H), 4.03 (q, 4H), 3.4-3.1 (m, 8H), 2.8-2.6 (m, 2H), 2.20 (m, 2H), 1.24 (t, 3H). Mass: (LC/MS APCI+): 597 (MH+). [α]_(D) = +9.32° (1% CH₃OH, 25° C.). 165 racemic 2 HCl ¹H-NMR (DMSO): 7.99 (d, 1H), 7.91 (s, 1H), 7.83 (s, 2H), 7.65-7.5 (m, 3H), 7.4-7.3 (m, 5H), 4.68 (s, 2H), 4.43 (s, 2H), 4.25 (q, 2H), 4.1-3.8 (m, 3H), 3.3-3.2 (m, 4H), 3.2-3.05 (m, 2H), 3.05- 2.9 (m, 2H), 1.27 (t, 3H). Mass: (LC/MS APCI+): 595 (MH+). 168 S, rac. 2 HCl.1 H₂O ¹H-NMR (DMSO): 7.89 (s, 1H), 7.82 (s, 2H), 7.5-7.2 (m, 5H), 4.75-4.6 (dd, 2H), 4.66 (s, 1H), 4.6-4.4 (m, 1H), 4.2-3.9 (m, 2H) 3.58 (s, 3H), 3.3-3.15 (m, 2H), 3.1-2.95 (m, 2H), 2.77 (m, 4H). Mass: (LC/MS APCI+): 581 (MH+). [α]_(D) = +16.47° (1% CH₃OH, 25° C.). 170 racemic 3 HCl.½ H₂O ¹H-NMR (DMSO): 8.68 (d, 1H), 8.2 (t, 1H), 7.95 (s, 1H), 7.9 (s, 2H), 7.76 (d, 1H), 7.7 (t, 1H), 7.6 (m, 2H), 7.45 (m, 3H), 4.73 (s, 2H), 4.67 (t, 1H), 4.26 (s, 2H), 4.2 (dd, 1H), 4.05 (dd, 1H), 3.5-3.4 (m, 2H), 3.2 (m, 6H). Mass: (EI/DIP): 523 (M+). 171 racemic — ¹H-NMR (DMSO): 7.9 (d, 1H), 7.75 (s, 1H), 7.64 (s, 2H), 7.5-7.1 (m, 8H), 4.57 (s, 2H), 4.3-4.1 (m, 2H), 4.0-3.7 (m, 6H), 3.65 (t, 1H), 3.14 (t, 2H), 2.7-2.5 (m, 2H), 2.5-2.3 (m, 2H). Mass: (LC/MS APCI+): 606 (MH+). 173 S 2 HCl ¹H-NMR (DMSO): 7.91 (s, 1H), 7.85 (s, 2H), 7.5-7.3 (m, 5H), 6.82 (s, 2H), 4.69 (s, 2H), 4.41 (t, 1H), 4.22 (s, 2H), 4.05 (dd, 1H), 3.95 (dd, 1H), 3.76 (s, 6H), 3.64 (s, 3H), 3.4-3.2 (m, 6H), 3.2- 3.05 (m, 2H). Mass: (EI/DIP): 612 (M+). [α]_(D) = +19,63° (1% CH₃OH, 25° C.). 174 R 2 HCl ¹H-NMR (DMSO): 7.92 (s, 1H), 7.85 (s, 2H), 7.5-7.3 (m, 5H), 6.81 (s, 2H), 4.68 (s, 2H), 4.33 (t, 1H), 4.19 (s, 2H), 4.05 (dd, 1H), 3.95 (dd, 1H), 3.76 (s, 6H), 3.64 (s, 3H), 3.4-3.15 (m, 6H), 3.1- 2.95 (m, 2H). Mass: (EI/DIP): 612 (M+). [α]_(D) = −20,09° (1% CH₃OH, 25° C.). 176 NSA 2 HCl ¹H-NMR (DMSO): 7.91 (s, 1H), 7.83 (s, 2H), 7.39 (m, 5H), 6.6 (s, 2H), 4.67 (s, 2H), 4.4 (s, 2H), 4.21 (t, 1H), 4.05-3.85 (m, 2H), 3.87 (s, 6H), 3.85 (m, 2H), 3.7 (s, 3H), 3.4-3.25 (m, 6H), 3.2- 2.9 (m, 4H). Mass: (EI/DIP): 656 (M+). [α]_(D) = +12,61° (1% CH₃OH, 25° C.). 177 NSB 2 HCl ¹H-NMR (DMSO): 7.9 (s, 1H), 7.81 (s, 2H), 7.38 (m, 5H), 6.6 (s, 2H), 4.66 (s, 2H), 4.39 (s, 2H), 4.21 (t, 1H), 4.05-3.85 (m, 2H), 3.92 (s, 6H), 3.9 (m, 2H), 3.69 (s, 3H), 3.4-3.25 (m, 6H), 3.2-2.9 (m, 4H). Mass: (EI/DIP): 656 (M+). [α]_(D) = −17,73° (1% CH₃OH, 25° C.). 182 NSA 2 maleate ¹H-NMR (DMSO): 7.99 (s, 1H), 7.89 (s, 2H), 7.49 (s, 1H), 7.39 (m, 3H), 6.17 (s, 4H), 4.70 (s, 2H), 4.05 (m, 1H), 3.95 (m, 2H), 3.71 (s, 2H), 3.68 (s, 3H), 3.1-2.9 (m, 6H), 2.8 (m, 2H). Mass: (LC/MS APCI): 539 (MH+). 188 racemic 2 maleate ¹H-NMR (DMSO): 8.00 (s, 1H), 7.85 (s, 2H), 7.4 (m, 1H), 7.26 (m, 2H), 6.18 (s, 4H), 4.69 (dd, 2H), 4.24 (t, 1H), 4.0-3.9 (m, 2H), 3.89 (s, 2H), 3.70 (s, 3H), 3.0 (m, 4H), 2.7 (m, 4H). Mass: (LC/MS APCI+): 541 (MH+). 191 racemic 2 HCl ¹H-NMR (DMSO): 8.21 (d, 1H), 7.85 (m, 2H), 7.81 (s, 1H), 7.75-7.65 (m, 3H), 7.5-7.4 (m, 3H), 4.98 (m, 1H), 4.62 (s, 2H), 4.1-3.9 (m, 2H), 3.67 (s, 2H), 3.3-3.15 (m, 6H), 3.15-2.95 (m, 2H). Mass: (LC/MS APCI+): 540 (MH+). 192 racemic — ¹H-NMR (DMSO): 7.98 (s, 1H), 7.95 (s, 2H), 7.41 (dd, 1H), 7.0-6.9 (m, 2H), 4.72 (s, 2H), 4.09 (t, 1H), 3.91 (dd, 1H), 3.82 (dd, 1H), 3.59 (s, 3H), 3.26 (s, 2H), 2.6-2.4 (m, 8H). Mass: (LC/MS APCI+): 511 (MH+). 193 racemic — ¹H-NMR (DMSO): 7.96 (s, 1H), 7.92 (s, 2H), 7.46 (m, 1H), 7.31 (d, 1H), 7.05 (dd, 1H), 4.69 (s, 2H), 4.0-3.75 (m, 3H), 3.59 (s, 3H), 3.25 (s, 2H), 2.6-2.35 (m, 8H). Mass: (LC/MS APCI+): 511 (MH+) 194 racemic — ¹H-NMR (DMSO): 7.97 (s, 1H), 7.93 (s, 2H), 7.57 (d, 1H), 6.41 (m, 1H), 6.29 (dd, 1H), 4.7 (dd, 2H), 4.0-3.8 (m, 3H), 3.58 (s, 3H), 3.26 (s, 2H), 2.5-2.3 (m, 8H). Mass: (LC/MS APCI+): 495 (MH+) 200 racemic — ¹H-NMR (DMSO): 7.35-7.2 (m, 5H), 7.0-6.85 (s + s, 2H), 6.5 (s, 2H), 4.38 (s, 2H), 3.99 (q, 1H), 3.8-3.3 (m, 2H), 3.71 (s, 6H), 3.64 (s, 3H), 2.7 (s, 2H), 2.5-2.4 (m, 8H). Mass: (LC/MS APCI+): 444 (MH+). 208 racemic 2 maleate ¹H-NMR (DMSO): 7.86 (s, 1H), 7.62 (s, 1H), 7.47 (s, 1H), 7.48 (m, 5H), 6.15 (s, 4H), 4.51 (s, 2H), 4.36 (m, 1H), 3.94 (m, 2H), 3.66 (s, 3H), 3.55 (s, 2H), 3.0-2.8 (m, 8H). Mass: (LC/MS APCI): 573/575 (MH+). 219 S, R 2 maleate ¹H-NMR (DMSO): 7.96 (s, 1H), 7.89 (s, 2H), 7.33 (m, 5H), 6.14 (s, 4H), 4.73 (q, 1H), 3.89 (s, 2H), 3.85-3.65 (m, 5H), 3.27 (t, 2H), 3.3-3.1 (m, 4H), 2.8-2.6 (m, 4H), 1.36 (m, 2H). Mass: (LC/MS APCI): 548 (MH+). [α]_(D) = +27 (1% CH₃OH, 25° C.).

1.4.2. Preparation of compounds of formula I according to process (a.2).

In a round-bottomed flask fitted with a reflux condenser and a thermometer 2.48 g (4 mmoles) of 5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-pentanoic acid ethyl ester (compound 140 prepared at example 1.4.1 above), 45 ml of ethyl alcohol, 4 ml of water, and 6.6 ml of a 1N solution of sodium hydroxide in water were introduced. The mixture was stirred at room temperature for 22 hours, and 6.6 ml of a 1N solution of hydrochloric acid in water was added. The volatile substances were removed under reduced pressure, water and methylene chloride were added, the aqueous layer was extracted with methylene chloride, and the combined organic phases were dried over magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in 35 ml of methylene chloride, 3.96 ml of a 1.96 N solution of hydrochloric acid in diethyl ether were added, and the volatile substances were removed under reduced pressure. The residue was recristallized from acetonitrile, affording 1.6 g of 5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-pentanoic acid (compound 233) as a solid. Yield: 61%.

The compounds listed in Table VII were obtained by the same method. Physico-chemical properties of the compounds of formula I prepared according to this method are given in Table VIIa below. When the compounds of formula I are in the form of non toxic pharmaceutically acceptable salts, they are obtained by the general methods given above.

TABLE VII Preparation of compounds of formula I by process (a.2) Stereo- Starting Cpd No. W chemistry Hydrolysis Cpd No 229 HOOC—CH₂— racemic KOH, room temp., 1 night 134 or 135 230 HOOC—CH₂— S KOH (3 eq), room temp., 4 h 144 or HCl 1 N, 100° C., 11 h 231 HOOC—CH₂— R KOH (2.5 eq), room temp., 145 1 night, or NaOH, EtOH, H₂O 232 HOOC—(CH₂)₃— racemic KOH (3 eq), EtOH, reflux, 1 h 138 233 HOOC—(CH₂)₄— racemic NaOH, EtOH, H₂O 140 234 HOOC—(CH₂)₅— racemic NaOH, EtOH, H₂O 141 or 150 235 HOOC—CH₂O(CH₂)₂— racemic HCl 1 N, 50° C., 1 night 147 236 HOOC—CH₂O(CH₂)₂— S HCl 6 N, 50° C., 3 h 30 148 237 HOOC—CH₂O(CH₂)₂— R HCl 6 N, 50° C. 1 night 149 238 HOOC—CH₂—NH—C(O)—CH₂— S KOH (2.5 eq), EtOH, 0-5° C., 290 2 h 239 (HO)₂(PO)(CH₂)₂— racemic HCl 6 N, 100° C., 4 days 163 240 (HO)(EtO)(PO)(CH₂)₂— S KOH (4 eq), EtOH, reflux, 164 24 h 241 2-(HOOC)—C₆H₄—CH₂— racemic KOH (2.5 eq), MeOH, 165 room temp., 48 h 242 3-(HOOC)—C₆H₄—CH₂— racemic KOH (6 eq), MeOH, reflux, 166 4 days 243 4-(HOOC)—C₆H₄—CH₂— S KOH (3 eq), MeOH, reflux, 167 1 night 244 C₆H₅CH(COOH)— S, rac HCl 6 N, CH₃COOH, 50° C., 168 7 days 245 HOOC—CH₂— racemic NaOH, EtOH, H₂O 178 246 HOOC—CH₂— racemic NaOH, EtOH, H₂O 179 247 HOOC—CH₂— racemic NaOH, EtOH, H₂O 180 248 HOOC—CH₂— NSA KOH (10 eq), EtOH, 182 reflux, 1 h 249 HOOC—CH₂— NSB KOH (10 eq), EtOH, 183 reflux, 6 h 250 HOOC—CH₂— racemic KOH, room temp., 48 h 184 251 HOOC—CH₂— NSA NaOH, EtOH, H₂O 186 252 HOOC—CH₂— NSB NaOH, EtOH, H₂O 187 253 HOOC—CH₂— racemic KOH (3 eq), MeOH, 188 reflux, 1 h 30 254 HOOC—CH₂— racemic NaOH, EtOH, H₂O 189 255 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 190 room t°, 48 h 256 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 192 room t°, 24 h 257 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 193 room t°, 24 h 258 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 194 room t°, 24 h 259 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 195 room t°, 48 h 260 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 196 room t°, 48 h 261 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 197 reflux, 2 h 262 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 198 reflux, 3 h 263 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 199 room temp., 24 h 264 HOOC—CH₂— racemic NaOH, EtOH, H₂O 201 265 HOOC—CH₂— racemic HCl 3 N, 50° C., 55 h 202 266 HOOC—CH₂— S NaOH, EtOH, H₂O 203 267 HOOC—CH₂— R NaOH, EtOH, H₂O 204 268 HOOC—CH₂— racemic HCl 3 N, 50° C., 24 h 205 269 HOOC—CH₂— racemic NaOH, EtOH, H₂O 206 270 HOOC—CH₂— racemic NaOH, EtOH, H₂O 207 271 HOOC—CH₂— racemic KOH (3 eq), MeOH, 208 reflux, 4 h 272 HOOC—CH₂— racemic NaOH, EtOH, H₂O 209 273 HOOC—CH₂— NSA KOH (3 eq), room temp., 4 h 210 274 HOOC—CH₂— NSB KOH (3 eq), room temp., 6 h 211 275 HOOC—CH₂— S, R HCl 10% 215 276 HOOC—CH₂— S, S HCl 10% 216 277 HOOC—CH₂— R, R HCl 10% 217 278 HOOC—CH₂— R, S HCl 10% 218 279 HOOC—CH₂O(CH₂)₂— S, R HCl 6 N, 50° C., 2 h 219 280 HOOC—CH₂O(CH₂)₂— S, S HCl 6 N, 50° C., 2 h 220 281 HOOC—CH₂O(CH₂)₂— R, R HCl 6 N, 50° C., 20 h 221 282 HOOC—CH₂O(CH₂)₂— R, S HCl 6 N, 50° C., 20 h 222 283 HOOC—CH₂— racemic KOH (2.5 eq), MeOH, 223 reflux, 4 h 284 3-(HOOC)—C₆H₄—CH₂— NSA KOH (2.5 eq), MeOH, 225 reflux, 4 h 285 3-(HOOC)—C₆H₄—CH₂— NSB KOH (3 eq), MeOH, 226 reflux, 3 h 286 HOOC—CH₂— racemic HCl 6 N, 50° C., 48 h 228

TABLE VIIa Physico-chemical properties of compounds of formula I Cpd Stereo- No. Free base/Salt chemistry Analysis 229 2 HCl racemic ¹H-NMR (DMSO): 7.97 (s, 1H), 7.94 (s, 2H), 7.62 (m, 2H), 7.4 (m, 2H), 4.74 (s, 2H), 4.6 (m, 1H), 4.35 (dd, 1H), 3.95 (dd, 1H), 3.95 (s, 2H), 3.5-3.3 (m, 6H), 3.3-3.1 (m, 2H). Mass: (LC/MS APCI+): 491 (MH+). 230 2 HCl.½ H₂O S ¹H-NMR (DMSO): 7.91 (s, 1H), 7.83 (s, 2H), 7.4 (m, 5H), 4.67 (s, 2H), 4.29 (t, 1H), 4.1-3.9 (m, 2H), 3.68 (s, 2H), 3.2-3.05 (m, 6H), 3.05-2.9 (m, 2H). Mass: (LC/MS APCI+): 491 (MH+). [α]_(D) = +12,6 (1% CH₃OH, 25° C.). 2 maleate ¹H-NMR (DMSO): 8.0 (s, 1H), 7.9 (s, 2H), 7.5-7.3 (m, 5H), 6.17 (s, 4H) 4.7 (s, 2H), 4.1-3.85 (m, 3H), 3.79 (s, 2H), 3.2-3.1 (m, 4H), 3.0-2.85 (m, 2H), 2.85-2.7 (m, 2H). Mass: (LC/MS APCI+): 491 (MH+). [α]_(D) = +5.8 (1% CH₃OH, 25° C.). 231 2 HCl.1 H₂O R ¹H-NMR (DMSO): 7.98 (s, 1H), 7.93 (s, 2H), 7.6 (m, 2H), 7.4 (m, 3H), 4.74 (s, 2H), 4.6-4.4 (m, 1H), 4.25 (m, 1H), 3.95 (dd, 1H), 3.91 (s, 2H), 3.5-3.3 (m, 6H), 3.2-2.9 (m, 2H). Mass: (LC/MS APCI+): 491 (MH+). [α]_(D) = −17.8 (1% CH₃OH, 25° C.). 2 maleate ¹H-NMR (DMSO): 7.98 (s, 1H), 7.89 (s, 2H), 7.39 (m, 5H), 6.15 (s, 4H), 4.70 (s, 2H), 4.1-3.9 (m, 3H), 3.76 (s, 2H), 3.2 (m, 4H), 3.0-2.8 (m, 4H). Mass: (LC/MS APCI+): 491 (MH+). [α]_(D) = −13.51 (1% CH₃OH, 25° C.). 232 2 maleate racemic ¹H-NMR (DMSO): 7.97 (s, 1H), 7.87 (s, 2H), 7.34 (m, 5H), 6.14 (s, 4H), 4.69 (s, 2H), 4.1-3.8 (m, 3H), 3.4-3.2 (m, 4H), 3.05 (t, 2H), 2.8-2.6 (m, 4H), 2.30 (t, 2H), 1.85 (m, 2H) Mass: (LC/MS APCI+): 519 (MH+). Mass: (LC/MS APCI−): 517 (M − H). 233 2 HCl racemic ¹H-NMR (DMSO): 7.98 (s, 1H), 7.96 (s, 2H), 7.65 (m, 2H), 7.45 (m, 3H), 4.74 (s, 2H), 4.65 (m, 1H), 4.3 (m, 1H), 4.0 (dd, 1H), 3.7-3.0 (m, 10H), 2.25 (t, 2H), 1.75-1.6 (m, 2H), 1.6-1.4 (m, 2H). Mass: (LC/MS APCI+): 533 (MH+). 234 {fraction (3/2)} maleate racemic ¹H-NMR (DMSO): 7.88 (s, 1H), 7.75 (s, 2H), 7.30 (m, 5H), 6.19 (s, 4H), 4.61 (s, 2H), 4.1-3.8 (m, 3H), 3.3-3.1 (m, 4H), 3.05 (t, 2H), 2.8-2.6 (m, 4H), 2.22 (t, 2H), 1.7-1.5 (m, 4H), 1.27 (m, 2H). Mass: (LC/MS APCI+): 547 (MH+). 235 2 maleate racemic ¹H-NMR (DMSO): 7.97 (s, 1H), 7.87 (s, 2H), 7.4-7.3 (m, 5H), 6.11 (s, 4H), 4.69 (s, 2H), 4.07 (s, 2H), 3.95-3.8 (m, 3H), 3.85 (t, 2H), 3.77 (t, 2H), 3.25 (m, 6H), 2.7 (m, 2H). Mass: (LC/MS APCI+): 535 (MH+). 2 HCl ¹H-NMR (DMSO): 7.9 (s, 1H), 7.85 (s, 2H), 7.5-7.3 (m, 5H), 4.7 (dd, 2H), 4.4 (t, 1H), 4.05 (s, 2H), 4.1-3.9 (m, 2H), 3.75 (t, 2H), 3.6-3.4 (m, 4H), 3.4-3.2 (m, 4H), 3.2-3.0 (m, 2H) Mass: (LC/MS APCI+): 535 (MH+). 236 2 HCl S ¹H-NMR (DMSO): 7.90 (s, 1H), 7.82 (s, 2H), 7.5-7.3 (m, 5H), 4.68 (m, 2H), 4.36 (m, 1H), 4.2- 3.9 (m, 4H), 3.75 (t, 2H), 3.5-3.0 (m, 10H). Mass: (LC/MS APCI+): 535 (MH+). 2 maleate ¹H-NMR (DMSO): 7.89 (s, 1H), 7.76 (s, 2H), 7.30 (m, 5H), 6.18 (s, 4H), 4.61 (s, 2H), 4.05 (s, 2H), 4.1-3.8 (m, 3H), 3.78 (t, 2H), 3.4-3.2 (m, 6H), 2.9-2.7 (m, 4H) Mass: (LC/MS APCI+): 535 (MH+). [α]_(D) = 9.87 (1% CH₃OH, 25° C.). 237 2 HCl R ¹H-NMR (DMSO): 7.90 (s, 1H), 7.79 (s, 2H), 7.3 (m, 5H), 4.64 (m, 2H), 4.2-3.9 (m, 5H), 3.73 (t, 2H), 3.4-2.8 (m, 10H). Mass: (LC/MS APCI+): 535 (MH+). 2 maleate ¹H-NMR (DMSO): 7.97 (s, 1H), 7.87 (s, 2H), 7.35 (m, 5H), 6.14 (s, 4H), 4.69 (s, 2H), 4.07 (s, 2H), 4.0-3.8 (m, 5H), 3.4-3.2 (m, 4H), 2.9-2.7 (m, 4H). Mass: (LC/MS APCI+): 535 (MH+). [α]_(D) = −12.82 (1% CH₃OH, 25° C.). 238 — S ¹H-NMR (DMSO): 7.86 (s, 1H), 7.75 (s, 2H), 7.35-7.15 (m, 5H), 4.6 (s, 2H), 3.8 (m, 2H), 3.65 (t, 1H), 3.57 (s, 2H), 2.95 (s, 2H), 2.55-2.45 (m, 8H). Mass: (LC/MS APCI+): 548 (MH+). [α]_(D) = +17.2 (1% CH₃OH, 25° C.). 239 2 HCl racemic ¹H-NMR (DMSO): 7.92 (s, 1H), 7.84 (s, 2H), 7.40 (m, 5H), 4.68 (s, 2H), 4.32 (t, 1H), 4.1-3.8 (m, 2H), 3.4 (m, 4H), 3.25 (m, 4H), 3.1 (m, 2H), 2.1-1.9 (m, 2H). Mass: (LC/MS APCI+): 540 (MH+). 240 2 maleate.1 H₂O S ¹H-NMR (DMSO): 7.97 (s, 1H), 7.86 (s, 2H), 7.34 (m, 5H), 6.12 (s, 4H), 4.68 (s, 2H), 4.1-3.8 (m, 5H), 3.3-3.1 (m, 6H), 2.9-2.6 (m, 4H), 2.1-1.9 (m, 2H), 1.19 (t, 3H). Mass: (LC/MS APCI+): 569 (MH+). 241 2 HCl.1 H₂O racemic ¹H-NMR (DMSO): 8.01 (d, 1H), 7.90 (s, 1H), 7.80 (s, 2H), 7.65-7.5 (m, 3H), 7.4-7.3 (m, 5H), 4.66 (s, 2H), 4.46 (s, 2H), 4.27 (t, 1H), 4.15-3.9 (m, 2H), 3.35 (m, 4H), 3.2-3.05 (m, 2H), 3.05- 2.9 (m, 2H). Mass: (LC/MS APCI+): 567 (MH+). 242 2 HCl.½ H₂O racemic ¹H-NMR (CDCl3): 8.17 (s, 1H), 7.94 (d, 1H), 7.7-7.55 (m, 4H), 7.5-7.3 (m, 6H), 4.65 (dd, 2H), 4.3 (m, 1H), 4.15-3.85 (m, 4H), 3.5-3.1 (m, 8H). Mass: (LC/MS APCI+): 567 (MH+). 243 2 maleate. S ¹H-NMR (DMSO): 7.98 (s, 1H), 7.95 (d, 2H), 7.88 (s, 2H), 7.59 (d, 2H), 7.38 (m, 5H), 6.17 (s, ½ H₂O 2H), 4.69 (s, 2H), 4.2 (s, 2H), 4.05 (m, 2H), 3.9 (m, 1H), 3.2-3.0 (m, 8H) Mass: (LC/MS APCI+): 567 (MH+). [α]_(D) = 18 (1% CH₃OH) 244 — S, rac. ¹H-NMR (DMSO): 7.87 (s, 1H), 7.75 (s, 2H), 7.4-7.15 (m, 10H), 4.59 (m, 2H), 4.22 (s, 1H), 3.8-3.6 (m, 3H), 3.05-2.9 (m, 4H), 2.8-2.5 (m, 4H). Mass: (LC/MS APCI+): 567 (MH+). [α]_(D) = +10.14 (1% CH₃OH, 25° C.) 245 1 H₂O racemic ¹H-NMR (DMSO): 8.0 (s, 1H), 7.85 (s, 2H), 7.25-7.15 (m, 4H), 4.85 (dd, 2H), 3.95 (dd, 1H), 3.85 (dd, 1H), 3.60 (t, 1H), 3.1 (s, 2H), 2.7-2.4 (m, 8H), 2.3 (s, 3H). Mass: (LC/MS APCI+): 505 (MH+). 246 2 maleate racemic ¹H-NMR (DMSO): 8.03 (s, 1H), 7.92 (s, 2H), 7.3-7.2 (m, 4H), 6.14 (s, 4H), 4.71 (s, 2H), 3.99 (m, 1H), 3.8 (m, 2H), 3.76 (s, 2H), 3.3-3.0 (m, 4H), 2.88 (m, 1H), 1.20 (d, 6H). Mass: (LC/MS APCI+): 533 (MH+). 247 2 HCl.{fraction (3/2)} H₂O racemic ¹H-NMR (DMSO): 7.92 (s, 1H), 7.85 (s, 2H), 7.42 (d, 2H), 6.96 (d, 2H), 4.7 (dd, 2H), 4.47 (t, 1H), 4.1-3.9 (m, 2H), 3.77 (s, 2H), 3.73 (s, 3H), 3.4-3.2 (m, 6H), 3.2-3.05 (m, 2H). Mass: (LC/MS APCI+): 521 (MH+) 248 2 maleate NSA ¹H-NMR (DMSO): 7.98 (s, 1H), 7.87 (s, 2H), 7.45 (s, 1H), 7.35 (m, 3H), 6.15 (s, 4H), 4.69 (s, 2H), 3.91 (m, 3H), 3.85 (s, 2H), 3.2 (m, 4H), 2.9-2.7 (m, 4H). Mass: (LC/MS APCI): 525/527 (MH+). [α]_(D) = 8.2 (1% CH₃OH). 249 2 maleate NSB ¹H-NMR (DMSO): 7.99 (s, 1H), 7.87 (s, 2H), 7.46 (s, 1H), 7.37 (m, 3H), 6.14 (s, 4H), 4.69 (s, 2H), 3.89 (m, 3H), 3.84 (s, 2H), 3.2 (m, 4H), 2.9-2.7 (m, 4H). Mass: (LC/MS APCI+): 525/527 (MH+). 250 2 HCl racemic ¹H-NMR (DMSO): 7.9 (s, 1H), 7.76 (s, 2H), 7.54 (d, 2H), 7.36 (d, 2H), 4.65 (dd, 2H), 4.16 (t, 1H), 4.05-3.85 (m, 2H), 3.82 (s, 2H), 3.3-3.15 (m, 4H), 3.15-3.0 (m, 2H), 3.0-2.8 (m, 2H). Mass: (LC/MS APCI+): 569/571 (MH+). 251 1 H₂O NSA ¹H-NMR (DMSO): 7.81 (s, 1H), 7.62 (s, 2H), 7.45 (m, 2H), 7.25 (d, 1H), 4.55 (s, 2H), 3.9-3.6 (m, 3H), 3.05 (s, 2H), 2.65-2.35 (m, 8H). Mass: (LC/MS APCI+): 559/561/563 (MH+). [α]_(D) = +6.65 (1% CH₃OH, 25° C.). 252 1 H₂O NSB ¹H-NMR (DMSO): 7.85 (s, 1H), 7.65 (s, 2H), 7.45 (m, 2H), 7.27 (d, 1H), 4.58 (s, 2H), 3.83 (m, 2H), 3.65 (t, 1H), 3.06 (s, 2H), 2.6-2.35 (m, 8H). Mass: (LC/MS APCI+): 559/561/563 (MH+). [α]_(D) = −8.91 (1% CH₃OH, 25° C.). 253 2 maleate racemic ¹H-NMR (DMSO): 7.99 (s, 1H), 7.85 (s, 2H), 7.4 (m, 2H), 7.24 (m, 1H), 6.16 (s, 4H), 4.70 (dd, 2H), 4.22 (t, 1H), 4.0-3.9 (m, 2H), 3.98 (s, 2H), 3.22 (m, 4H), 2.75 (m, 4H). Mass: (LC/MS APCI+): 527 (MH+). 254 ½ H₂O racemic ¹H-NMR (DMSO): 7.94 (s, 1H), 7.77 (s, 2H), 7.28 (dd, 2H), 4.64 (s, 2H), 3.81 (d, 2H), 3.65 (t, 1H), 3.08 (s, 2H), 2.6-2.35 (m, 8H). Mass: (LC/MS APCI+): 545 (MH+). 255 2 HCl racemic ¹H-NMR (DMSO): 8.4 (s, 1H), 8.22 (dd, 2H), 7.98 (d, 1H), 7.98 (s, 1H), 7.85 (s, 2H), 7.7 (t, 1H), 4.71 (s, 2H), 4.4 (m, 1H), 4.1-3.9 (m, 2H), 4.04 (s, 2H), 3.5-2.9 (m, 8H). Mass: (LC/MS APCI+): 536 (MH+). 256 — racemic ¹H-NMR (DMSO): 7.91 (s, 1H), 7.86 (s, 2H), 7.38 (m, 1H), 6.98 (d, 1H), 4.65 (s, 2H), 4.11 (t, 1H), 3.9-3.75 (m, 2H), 3.25 (s, 2H), 3.1-2.9 (m, 4H), 2.7-2.55 (m, 4H). Mass: (LC/MS APCI+): 497 (MH+). 257 — racemic ¹H-NMR (DMSO): 7.89 (s, 1H), 7.81 (s, 2H), 7.43 (m, 1H), 7.32 (d, 1H), 7.04 (dd, 1H), 4.63 (s, 2H), 4.0-3.75 (m, 3H), 3.33 (s, 2H), 3.2-3.0 (m, 4H), 2.7-2.55 (m, 4H). Mass: (LC/MS APCI+): 497 (MH+). 258 — racemic ¹H-NMR (DMSO): 7.97 (s, 1H), 7.93 (s, 2H), 7.58 (d, 1H), 6.42 (m, 1H), 6.32 (dd, 1H), 4.71 (dd, 2H), 4.0-3.8 (m, 3H), 3.2 (s, 2H), 2.7-2.55 (m, 4H), 2.55-2.4 (m, 4H). Mass: (LC/MS APCI+): 481 (MH+). 259 — racemic ¹H-NMR (DMSO): 7.87 (s, 3H), 7.85-7.75 (m, 1H), 7.72 (m, 1H), 6.65 (m, 3H), 4.68 (s, 2H), 4.2 (t, 1H), 3.9-3.75 (m, 2H), 3.4 (s, 2H), 3.2-3.0 (m, 4H), 2.85-2.7 (m, 4H). Mass: (LC/MS APCI+): 547 (MH+). 260 — racemic ¹H-NMR (DMSO): 7.94 (s, 3H), 7.58 (dd, 1H), 7.49 (d, 1H), 7.3-7.15 (m, 3H), 4.74 (dd, 2H), 4.12 (t, 1H), 3.99 (d, 2H), 3.07 (s, 2H), 2.75-2.5 (m, 8H). Mass: (LC/MS APCI+): 531 (MH+). 261 — racemic ¹H-NMR (DMSO): 7.35 (s, 5H), 6.86 (s, 1H), 6.77 (s, 2H), 4.38 (s, 2H), 3.9-3.7 (m, 3H), 3.45 (s, 2H), 3.1-2.7 (m, 8H), 2.15 (s, 6H). Mass: (LC/MS APCI+): 383 (MH+). 262 — racemic ¹H-NMR (CDCl3): 7.3-7.1 (m, 7H), 6.9-6.7 (m, 2H), 4.5 (s, 2H), 3.8-3.6 (m, 3H), 3.78 (s, 3H), 3.36 (s, 2H), 3.25-3.0 (m, 4H), 2.9-2.6 (m, 4H). Mass: (LC/MS APCI+): 385 (MH+). 263 — racemic ¹H-NMR (DMSO): 7.45-7.25 (m, 5H), 7.16 (t, 1H), 6.73 (d, 2H), 6.67 (s, 1H), 4.44 (m, 1H), 4.41 (s, 2H), 3.85-3.65 (m, 3H), 3.35 (s, 2H), 3.1 (m, 4H), 2.7-2.5 (m, 4H), 1.18 (d, 6H). Mass: (LC/MS APCI+): 413 (MH+). 264 1 maleate. racemic ¹H-NMR (DMSO): 7.4-7.2 (m, 9H), 6.14 (s, 4H), 4.52 (s, 2H), 4.2 (m, 1H), 4.05 (m, 1H), 3.9 ⅓ H₂O (m, 1H), 3.68 (s, 2H), 3.2-3.0 (m, 4H), 3.0-2.8 (m, 4H). Mass: (LC/MS APCI+): 389/391 (MH+). 266 — S ¹H-NMR (DMSO): 7.45 (t, 1H), 7.4-7.2 (m, 5H), 7.22 (d, 2H), 4.47 (s, 2H), 3.85 (dd, 1H), 3.73 (t, 1H), 3.66 (dd, 2H), 3.16 (s, 2H), 2.7 (m, 4H), 2.6-2.4 (m, 4H). Mass: (LC/MS APCI+): 423/425/427 (MH+). [α]_(D) = +8.9 (1% CH₃OH, 25° C.). 267 — R ¹H-NMR (DMSO): 7.45 (t, 1H), 7.4-7.2 (m, 5H), 7.22 (d, 2H), 4.47 (s, 2H), 3.85 (dd, 1H), 3.73 (t, 1H), 3.66 (dd, 2H), 3.14 (s, 2H), 2.65 (m, 4H), 2.6-2.4 (m, 4H). Mass: (LC/MS APCI+): 423/425/427 (MH+). [α]_(D) = +13.45 (1% CH₃OH, 25° C.). 268 2 HCl racemic ¹H-NMR (DMSO): 7.51 (d, 1H), 7.4 (m, 6H), 7.22 (d, 2H), 4.5 (s, 2H), 4.33 (t, 1H), 4.05-3.8 (m, 2H), 3.69 (s, 2H), 3.2-3.1 (m, 6H), 3.05 (m, 2H). Mass: (LC/MS APCI+): 423/425/427 (MH+). 269 2 maleate racemic ¹H-NMR (DMSO): 7.74 (s, 1H), 7.45 (s, 2H), 7.40 (m, 5H), 6.15 (s, 4H), 4.52 (s, 2H), 4.05 (m, 1H), 3.9-3.8 (m, 2H), 3.78 (s, 2H), 3.1 (m, 4H), 2.8 (m, 4H). Mass: (LC/MS APCI+): 511/513/515 (MH+). 270 2 maleate racemic ¹H-NMR (DMSO): 7.45 (d, 1H), 7.36 (s, 5H), 7.10 (m, 2H), 6.95 (d, 1H), 6.07 (s, 4H), 4.52 (s, 2H), 4.49 (s, 2H), 3.9 (m, 2H), 3.85 (m, 1H), 3.7-3.5 (m, 4H), 3.0-2.7 (m, 4H). Mass: (LC/MS APCI+): 391 (MH+). 271 1 maleate.1 H₂O racemic ¹H-NMR (DMSO): 7.84 (s, 1H), 7.61 (s, 1H), 7.44 (s, 1H), 7.4 (m, 5H), 6.22 (s, 4H), 4.48 (s, 2H), 4.1-3.7 (m, 5H), 3.2-3.0 (m, 6H, 2.9 (m, 2H). Mass: (LC/MS APCI+): 559/561 (MH+). 272 ⅔ H₂O racemic ¹H-NMR (DMSO): 8.00 (s, 2H), 7.98 (s, 1H), 7.25 (m, 3H), 7.15 (m, 2H), 4.0-3.65 (m, 3H), 3.07 (s, 2H), 2.6-2.3 (m, 8H). Mass: (LC/MS APCI+): 491 (MH+). 273 2 HCl.3 H₂O NSA ¹H-NMR (DMSO): 7.87 (s, 1H), 7.81 (s, 2H), 7.5-7.3 (m, 5H), 4.7 (q, 1H), 4.35 (t, 1H), 3.95 (dd, 1H), 3.77 (s, 2H), 3.57 (dd, 1H), 3.4-3.1 (m, 6H), 3.1-3.0 (m, 2H), 1.41 (d, 3H). Mass:. (LC/MS APCI+): 505 (MH+). 274 2 HCl.1 H₂O NSB ¹H-NMR (DMSO): 7.89 (s, 1H), 7.8 (s, 2H), 7.4-7.3 (m, 5H), 4.71 (q, 1H), 4.35 (t, 1H), 4.1-3.9 (dd, 1H), 3.8 (s, 2H), 3.65 (dd, 1H), 3.4-3.1 (m, 6H), 3.1-2.95 (m, 2H), 1.35 (d, 3H). Mass: (LC/MS APCI+): 505 (MH+). 275 2 HCl.{fraction (5/2)} H₂O S, R ¹H-NMR (DMSO): 7.91 (s, 1H), 7.85 (s, 2H), 7.5-7.4 (m, 5H), 4.73 (q, 1H), 4.44 (t, 1H), 3.89 (s, 2H), 3.99 (m, 1H), 3.58 (m, 1H), 3.41 (m, 2H), 3.36 (m, 4H), 3.16 (m, 2H), 1.41 (d, 3H) Mass: (LC/MS APCI+): 505 (MH+). [α]_(D) = +31,38; +23,65° (1% DMSO 25° C.). 276 2 HCl.1 H₂O S, S ¹H-NMR (DMSO): 7.93 (s, 1H), 7.82 (s, 2H), 7.4 (m, 5H), 4.70 (q, 1H), 4.35 (t, 1H), 4.00 (m, 1H), 3.78 (s, 2H), 3.66 (m, 1H), 3.23 (m, 4H), 3.20 (m, 2H), 3.04 (m, 2H), 1.35 (d, 3H). Mass: (LC/MS APCI+): 505 (MH+). [α]_(D) = −14,33° (1% DMSO 25° C.). 277 2 HCl.1 H₂O R, R ¹H-NMR (DMSO): 7.92 (s, 1H), 7.82 (s, 2H), 7.4 (m, 5H), 4.71 (q, 1H), 4.34 (t, 1H), 4.00 (m, 1H), 3.79 (s, 2H), 3.66 (m, 1H), 3.23 (m, 4H), 3.20 (m, 2H), 3.04 (m, 2H), 1.36 (d, 3H). Mass: (LC/MS APCI+): 505 (MH+). [α]_(D) = +13,41 (1% DMSO 25° C.). 278 2 HCl.{fraction (5/2)} H₂O R, S ¹H-NMR (DMSO): 7.91 (s, 1H), 7.84 (s, 2H), 7.5-7.4 (m, 5H), 4.72 (q, 1H), 4.44 (t, 1H), 3.89 (s, 2H), 3.99 (m, 1H), 3.58 (m, 1H), 3.41 (m, 2H), 3.36 (m, 4H), 3.16 (m, 2H), 1.40 (d, 3H). Mass: (LC/MS APCI+): 505 (MH+). [α]_(D) = −31,66; −23,83° (1% DMSO 25° C.). 279 2 HCl.1 H₂O S, R ¹H-NMR (DMSO): 7.88 (s, 1H), 7.80 (s, 2H), 7.4-7.3 (m, 5H), 4.68 (q, 1H), 4.2-4.0 (m, 1H), 4.06 (s, 2H), 3.95-3.8 (m, 1H), 3.75 (t, 2H), 3.65-3.5 (m, 1H), 3.4-3.3 (m, 4H), 3.28 (t, 2H), 3.25-3.1 (m, 2H), 3.1-2.9 (m, 2H), 1.38 (d, 3H). Mass: (LC/MS APCI+): 549 (MH+). [α]_(D) = +26,55° (1% CH₃OH, 25° C.). 280 2 HCl.1 H₂O S, S ¹H-NMR (DMSO): 7.89 (s, 1H), 7.79 (s, 2H), 7.5-7.3 (m, 5H), 4.69 (q, 1H), 4.26 (t, 1H), 4.1- 3.95 (m, 1H), 4.05 (s, 2H), 3.75 (t, 2H), 3.7-3.6 (m, 1H), 3.5-3.3 (m, 4H), 3.29 (t, 2H), 3.3-3.15 (m, 2H), 3.15-3.0 (m, 2H), 1.34 (d, 3H). Mass: (LC/MS APCI+): 549 (MH+). [α]_(D) = −3.51 (1% CH₃OH, 25° C.). 281 2 HCl.½ H₂O R, R ¹H-NMR (DMSO): 7.86 (s, 1H), 7.81 (s, 2H), 7.5-7.3 (m, 5H), 4.73 (q, 1H), 4.54 (t, 1H), 4.15- 4.0 (m, 1H), 4.06 (s, 2H), 3.8-3.65 (m, 3H), 3.6-3.5 (m, 4H), 3.5-3.3 (m, 4H), 3.25-3.1 (m, 2H), 1.35 (d, 3H). Mass: (LC/MS APCI+): 549 (MH+). [α]_(D) = +1.77° (1% CH₃OH, 25° C.). 282 2 HCl.½ H₂O R, S ¹H-NMR (DMSO): 7.89 (s, 1H), 7.80 (s, 2H), 7.4-7.3 (m, 5H), 4.68 (q, 1H), 4.1-4.0 (m, 1H), 4.06 (s, 2H), 3.95-3.8 (m, 1H), 3.74 (t, 2H), 3.6-3.5 (m, 1H), 3.4-3.3 (m, 4H), 3.26 (t, 2H), 3.15-3.0 (m, 2H), 3.0-2.85 (m, 2H), 1.37 (d, 3H). Mass: (LC/MS APCI+): 549 (MH+). [α]_(D) = −30,67° (1% CH₃OH, 25° C.). 283 2 HCl.{fraction (3/2)} H₂O racemic ¹H-NMR (DMSO): 7.94 (s, 1H), 7.88 (s, 2H), 7.5-7.35 (m, 5H), 4.72 (s, 2H), 4.67 (m, 1H), 4.1- 3.8 (m, 2H), 3.98 (s 2H), 3.7-3.5 (m, 4H), 3.4-3.2 (m, 4H), 2.15-2.0 (m, 2H). Mass: (LC/MS APCI+): 505 (MH+). 284 2 maleate.1 H₂O NSA ¹H-NMR (DMSO): 8.11 (s, 1H), 8.0 (m, 2H), 7.89 (s, 2H), 7.7 (d, 1H), 7.55 (t, 1H), 7.4-7.25 (m, 5H), 6.14 (s, 4H), 4.7 (s, 2H), 4.31 (s, 2H), 4.16 (t, 1H), 4.0-3.8 (m, 2H), 3.2-2.95 (m, 6H), 3.85 (m, 2H), 1.9 (m, 2H). Mass: (LC/MS APCI+): 581 (MH+). [α]_(D) = −5.80 (1% CH₃OH, 25° C.). 285 2 maleate.1 H₂O NSB ¹H-NMR (DMSO): 8.11 (s, 1H), 8.0 (m, 2H), 7.89 (s, 2H), 7.7 (d, 1H), 7.55 (t, 1H), 7.4-7.25 (m, 5H), 6.15 (s, 4H), 4.7 (s, 2H), 4.31 (s, 2H), 4.16 (t, 1H), 4.0-3.8 (m, 2H), 3.2-2.95 (m, 6H), 3.85 (m, 2H), 1.92 (m, 2H). Mass: (LC/MS APCI+): 581 (MH+). [α]_(D) = +2.30 (1% CH₃OH, 25° C.). 286 2 HCl.2 H₂O racemic ¹H-NMR (DMSO): 7.75 (s, 1H), 7.69 (s, 2H), 7.2 (m, 5H), 4.26 (t, 2H), 4.67 (m, 1H), 3.91 (dd, 2H), 3.84 (s 2H), 3.45-3.05 (m, 10H). Mass: (LC/MS APCI+): 507 (MH+).

1.4.3. Preparation of compounds of formula I according to process (a.3).

1.4.3.1. (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}ethoxy)-acetic acid isobutyl ester (compound 287) dichlorhydrate monohydrate.

In a round-bottomed flask fitted with a reflux condenser and a thermometer were introduced (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic acid (compound 235, 0.5 g, 0.84 mmoles) dissolved in THF (20 ml). To this solution cooled at 0° C. were successively added isobutanol (0.155 ml, 1.68 mmoles), DMAP (0.01 g, 0.084 mmoles) and EDCI (0.177 g, 0.93 mmoles). The reaction mixture was stirred for 2 hours at 0° C. and then allowed to reach room temperature and stirred overnight. The organic solution was washed with HCl 0.1N and water, dried over MgSO₄ and concentrated. The resulting oil was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/NH₃: 99.5/0.5/0.1 v/v/v) to yield (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic acid isobutyl ester (compound 287, 390 mg, 65%) which was converted into its dihydrochloride monohydrate salt by reaction with HCl in diethylether.

Analysis for dihydrochloride monohydrate salt of compound 287:

¹H-NMR (DMSO): 7.95 (s, 1H), 7.9 (s, 2H), 7.5-7.3 (m, 5H), 4.7 (dd, 2H), 4.4 (t, 1H), 4.1 (s, 2H), 4.05-3.85 (m, 2H), 3.8 (d, 2H), 3.85-3.7 (m, 2H), 3.55-3.05 (m, 10H), 1.7 (m, 1H), 0.8 (d, 6H).

Mass: (LC/MS APCI+): 591 (MH+).

1.4.3.2. 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-butyramide (compound 288).

In a round-bottomed flask fitted with a reflux condenser are introduced 493 mg (0.9 mmoles) of 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-butyric acid ethyl ester (compound 138 prepared at example 1.4.1 above), 15 ml of formamide and 97 mg (1.8 mmoles) of sodium methoxide. The mixture is heated to 95° C. for 4 hours, then 48 mg (0.9 mmole) of sodium methoxide are added and the mixture is kept overnight at 85° C. The mixture is cooled and partitioned between diethyl ether (100 ml) and brine (100 ml). The organic phase is dried and volatile substances are removed under reduced pressure, affording 400 mg of 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-butyramide as a yellow oil (yield 86%). The dimaleate salt of compound 288 is prepared in 2-butanone (yield: 4.32 g as a white solid).

Analysis for dimaleate of compound 288:

¹H-NMR (DMSO): 8.00 (s, 1H), 7.87 (s, 2H), 7.44 (s, 1H), 7.33 (m, 5H), 6.95 (s, 1H), 4.68 (dd, 2H), 3.9.1-3.8 (m, 3H), 3.9-3.4 (m, 8H), 3.0 (t, 2H), 2.14 (t, 2H), 1.78 (m, 2H).

Mass: (LC/MS APCI+): 518 (MH+).

1.4.3.3. (S)-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetonitrile dichlorhydrate (compound 291).

In a round-bottomed flask fitted with a reflux condenser and a thermometer were introduced 3 g (6.13 mmoles) of (S)-2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetamide dissolved in 30 ml of CH₂Cl₂ (compound 144 prepared at example 1.4.1 above). The solution was cooled to −78° C. and DMSO (0.7 ml, 9.8 mmoles) and oxalyl chloride (0.6 ml, 7.4 mmoles) were added. After 15 minutes, triethylamine (2.5 ml, 18.4 mmoles) was added dropwise and the reaction mixture was stirred at −70° C. until complete disappearance of the starting material. The reaction was quenched with water and the pH was adjusted to 11 by addition of aqueous NaOH. The aqueous solution was extracted with CH₂Cl₂ and the combined organic layers were dried over MgSO₄ and concentrated. The crude was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/NH₃: 98/2/0.2 v/v/v) to yield (S)-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetonitrile (compound 291, 2.14 g, 73%) as a pale yellow powder which was converted into the dichydrochloride salt by reaction with HCl in diethylether.

Analysis for Dihydrochloride of Compound 291

¹H-NMR (DMSO): 7.95 (s, 1H), 7.9 (s, 2H), 7.55-7.35 (m, 5H), 4.72 (dd, 2H), 4.6 (t, 1H), 4.07 (d, 2H), 3.72 (s, 2H), 3.15 (m, 4H), 2.75 (m, 4H).

Mass: (LC/MS APCI+): 472 (MH+).

[α]D=+11.2° (1% CH₃OH, 25° C.).

1.4.3.4. 2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-N-methyl-acetamide (compound 292)

In a round-bottomed flask fitted with a reflux condenser and a thermometer are introduced 1.5 g (3 mmoles) of {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid (compound 229 prepared at example 1.4.2 above), 7 ml of THF and 7 ml of acetonitrile. Then 1.85 ml (3.7 mmoles) of a 2M solution of methylamine in THF are added, followed by 234 mg (1.5 mmoles) of HOBT, 1.33 ml (7.6 mmoles) of diisopropylethylamine and 880 mg (4.3 mmoles) of DCC. The mixture is stirred until completion of the reaction, and filtered. Volatile substances are removed under reduced pressure, and the residue is partitioned between ethyl acetate and 0.1 N sodium hydroxide. The organic phase is washed with brine, dried over magnesium sulfate and volatile substances are removed under reduced pressure. This yields crude 2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-N-methyl-acetamide (compound 292) which is directly converted into its dimaleate salt in 2-butanone (1.44 g of a white solid; yield 65%).

The compounds 290, 293 and 294 (Table VIII) were obtained by the same method. Physico-chemical properties of the compounds of formula I prepared according to this method are given in Table VIIIa below. When the compounds of formula I are in the form of non toxic pharmaceutically acceptable salts, they are obtained by the general methods given above.

TABLE VIII Preparation of compounds 290, 293 and 294. Stereo- Conditions Cpd No. W chemistry material I Starting 290 H₃COOC—CH₂—NH—CO—CH₂— S H₂N—CH₂—COOCH₃, 231 EDCI, HOBT 293 (tBu)NH—CO—CH₂— racemic NH₂tBu, EDCI, HOBT 229 294 (tBu)(CH₃)NH—CO—CH₂— racemic NtBuCH₃, EDCI, HOBT 229

TABLE VIIIa Physico-chemical properties of compounds of formula I Cpd Free base/ Stereo No. Salt chemistry Analysis 292 2 maleate racemic ¹H-NMR (DMSO): 8.2 (s, 2H), 8.0 (s, 1H), 7.5 (m, 2H), 6.3 (s, 4H), 4.8 (s, 2H), 4.0-3.8 (m, 3H), 3.6 (m, 2H), 3.2-2.8 (m, 8H), 2.7 (s, 3H). SM (LC/MS APCI+): 504 (MH+). 293 2 maleate racemic ¹H-NMR (DMSO): 7.9 (s, 1H), 7.8 (s, 2H), 7.3 (m, 5H), 6.2 (s, 4H), 4.7 (s, 2H), 3.9 (m, 3H), 3.5 (m, 2H), 2.6-3.2 (m, 8H), 1.2 (s, 9H). SM (LC/MS APCI+): 546 (MH+). 294 2 maleate racemic ¹H-NMR (DMSO): 7.97 (s, 1H), 7.87 (s, 2H), 7.35 (m, 5H), 6.13 (s, 4H), 4.68 (s, 2H), 4.12 (s, 2H), 4.0- 3.8 (m, 3H), 3.3-3.0 (m, 6H), 2.79 (s, 3H), 2.75 (m, 2H), 1.37 (s, 9H). SM (LC/MS APCI+): 560 (MH+).

1.4.4. Preparation of compounds of formula I according to process (a.4).

5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-2,4-dihydro-[1,2,4]triazol-3-one (compound 295) is prepared by reacting 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazine (compound 86 prepared at example 1.3.1 above) with N′-(2-Chloro-1-imino-ethyl)-hydrazinecarboxylic acid methyl ester according to the procedure described by Ladduwahetty T. et al., J. Med. Chem. (1996), 39, 2907-2914.

Analysis for compound 295:

¹H-NMR (DMSO): 7.95 (s, 1H), 7.85 (s, 2H), 7.35-7.25 (m, 5H), 4.65 (s, 2H), 3.9 (dd, 1H), 3.8 (dd, 1H), 3.65 (t, 1H), 3.21 (s, 2H), 2.5-2.35 (m, 8H).

Mass: (LC/MS APCI+): 530 (MH+).

1.4.5. Preparation of compounds of formula I according to process (a.5).

In a round-bottomed flask fitted with a reflux condenser and a thermometer 7.2 g (14 mmoles) of (S)-5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-pentanenitrile (compound 153, prepared at example 1.4.1 above), 25 ml of toluene, 3.9 g (15 mmoles) of dibutyl tin oxide, and 3.3 g (28 mmoles) of trimethyl silyl azide were introduced. The mixture was heated at reflux for 18 hours, the volatile substances were removed under reduced pressure and the residue was washed with methyl alcohol, affording 11.4 g of crude product. The product was purified by chromatography on silica gel (eluant: methylene chloride-methanol-aqueous ammonia 90/10/1 (v/v/v)), affording 6.2 g of an oil (yield 80%). The product was dissolved in 50 ml of diisopropyl ether, the solution was filtered, and 13 ml of a 1.88N solution of hydrochloric acid in diethyl ether were added to the filtrate. The mixture was stirred for 16 hours and filtered. The precipitate was collected and recrystallized from acetonitrile, affording 4.2 g of (S)-1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-4-[4-(1H-tetrazol-5-yl)-butyl]-piperazine (compound 298) as its dihydrochloride. Yield: 48%.

The compounds listed in Table IX were obtained by the same method. Physico-chemical properties of the compounds of formula I prepared according to this method are given in Table IXa below. When the compounds of formula I are in the form of non toxic pharmaceutically acceptable salts, they are obtained by the general methods given above.

TABLE IX Preparation of compounds of formula by process (a.2) Cpd Stereo- Starting No. chemistry n′ R2 Ar¹ Ar² Z W* cpd No 296 S 1 H phenyl 3,5-bis(trifluoromethyl)- O Tet-CH₂— 291 phenyl 297 racemic 1 H phenyl 3,5-bis(trifluoromethyl)- O Tet-(CH₂)₄— 152 phenyl 299 R 1 H phenyl 3,5-bis(trifluoromethyl)- O Tet-(CH₂)₄— 154 phenyl 300 racemic 1 H phenyl 3,5-bis(trifluoromethyl)- O Tet-CH₂O(CH₂)₂— 155 phenyl 301 racemic 1 H 4-fluoro- 3,5-bis(trifluoromethyl- O Tet-(CH₂)₄— 185 phenyl phenyl 302 NSA 1 CH₃ phenyl 3,5-bis(trifluoromethyl)- O Tet-(CH₂)₄— 212 phenyl 303 NSB 1 CH₃ phenyl 3,5-bis(trifluoromethyl)- O Tet-(CH₂)₄— 213 phenyl 304 racemic 1 CH₃ phenyl 3,5-bis(trifluoromethyl)- O Tet-(CH₂)₅— 156 phenyl *Tet means tetrazol.

TABLE IXa Physico-chemical properties of compounds of formula I. Cpd Stereo- No. chemistry Salt Characteristics 296 S 2 HCl.1 H2O ¹H-NMR (DMSO): 7.92 (s, 1H), 7.85 (s, 2H), 7.55-7.35 (m, 5H), 4.7 (s, 2H), 4.55 (t, 1H), 4.1-3.9 (m, 4H), 3.3 (m, 2H), 3.1 (m, 2H), 2.8 (m, 4H). SM (LC/MS APCI+): 515 (MH+). [α]_(D) = +19 (1% CH3OH, 25° C.). 297 racemic 2 HCl ¹H-NMR (DMSO): 7.91 (s, 1H), 7.81 (s, 2H), 7.35 (m, 5H), 4.66 (s, 2H), 4.2 (m, 1H), 4.1-3.9 (m, 2H), 3.4-3.2 (m, 4H), 3.2-2.9 (m, 6H), 2.89 (t, 2H), 1.7-1.5 (m, 4H). SM (LC/MS APCI+): 557 (MH+) 298 S 2 HCl ¹H-NMR (DMSO): 7.95 (s, 1H), 7.9 (s, 2H), 7.55 (m, 2H), 7.4 (m, 3H), 4.7 (s, 2H), 4.6 (t, 1H), 4.1-3.9 (m, 2H), 3.55-2.85 (m, 12H), 1.8-1.55 (m, 4H). SM (LC/MS APCI+): 557 (MH+). [α]_(D) = +16 (1% CH₃OH, 25° C.). 299 R 2 HCl ¹H-NMR (DMSO): 7.92 (s, 1H), 7.83 (s, 2H), 7.45-7.35 (m, 5H), 4.68 (s, 2H), 4.68 (t, 1H), 4.05-3.9 (m, 2H), 3.4-3.25 (m, 4H), 3.15-2.85 (m, 8H), 1.8-1.55 (m, 4H). SM (LC/MS APCI+): 557 (MH+). [α]_(D) = +18.95 (1% CH₃OH, 25° C.). 300 racemic 2 HCl ¹H-NMR (DMSO): 7.92 (s, 1H), 7.83 (s, 2H), 7.45-7.35 (m, 5H), 4.85 (s, 2H), 4.67 (s, 2H), 4.25 (t, 1H), 4.1- 3.75 (m, 4H), 3.45-3.25 (m, 6H), 3.2-2.9 (m, 4H). SM (LC/MS APCI+): 559 (MH+). 301 racemic 2 HCl. ¹H-NMR (DMSO): 7.98 (s, 1H), 7.9 (s, 2H), 7.6 (m, 2H), ⅓ C₃H₈O 7.25 (t, 2H), 4.72 (s, 2H), 4.45 (m, 1H), 4.15 (m, 1H), 3.95 (m, 1H), 3.75 (se, 1/3H), 3.6-3.0 (m, 10H), 2.92 (t, 2H), 1.8-1.6 (m, 4H), 1.04 (d, 2H). SM (LC/MS APCI+): 575 (MH+). 302 NSA 2 HCl ¹H-NMR (DMSO): 7.9 (s, 1H), 7.8 (s, 2H), 7.45-7.25 (m, 5H), 4.7 (q, 1H), 4.3 (t, 1H), 4.05 (dd, 1H), 3.65 (dd, 1H), 3.5-2.95 (m, 10H), 2.9 (t, 2H), 1.7-1.55 (m, 4H), 1.35 (d, 3H). SM (LC/MS APCI+): 571 (MH+). 303 NSB 2 HCl ¹H-NMR (DMSO): 7.91 (s, 1H), 7.81 (s, 2H), 7.45-7.25 (m, 5H), 4.7 (q, 1H), 4.28 (t, 1H), 4.05 (dd, 1H), 3.65 (dd, 1H), 3.5-2.95 (m, 10H), 2.9 (t, 2H), 1.7-1.55 (m, 4H), 1.35 (d, 3H). SM (LC/MS APCI+): 571 (MH+). 304 racemic 2 maleate ¹H-NMR (DMSO): 7.97 (s, 1 H), 7.87 (s, 2H), 7.35 (m, 5H), 6.14 (s, 4H), 4.69 (s, 2H), 4.05-3.8 (m, 3H), 3.3- 3.1 (m, 4H), 3.04 (t, 2H), 2.91 (t, 2H), 2.8-2.6 (m, 4H), 2.04 (t, 2H), 1.85-1.7 (m, 2H), 1.7-1.5 (m, 2H), 1.32 (m, 2H). SM (LC/MS APCI+): 571 (MH+).

1.4.6. Preparation of compounds of formula I according to process (a.6).

1.4.6.1. Synthesis of N-[(2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetyl]-methanesulfonamide (compound 305).

In a round-bottomed flask fitted with a reflux condenser and a thermometer, 0.5 g (0.8 mmoles) of the dihydrochloride of (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic acid (compound 235) and 10 ml of dichloromethane, were introduced under nitrogen. The solution was cooled to 0° C. and 0.1 ml (1.2 mmoles) of oxalyl chloride were added. The reaction mixture was stirred at room temperature for one night. Again, 1 ml (12 mmoles) of oxalyl chloride were added. After 2 hours, the mixture was concentrated under reduced pressure. The residue was dissolved in dichloromethane and a solution of 0.075 g (0.8 mmoles) of methanesulfonamide and 0.12 ml (0.8 mmoles) of triethylamine in 5 ml of tetrahydrofuran, were added dropwise. The mixture was stirred at room temperature for one night. The solution was washed with water and brine. The organic phase was dried over magnesium sulfate and concentrated under reduced pressure affording 0.33 g of crude product. This was purified by chromatography on silica gel (eluent: CH₂Cl₂/CH₃OH: 95/5) affording 0.129 g of an oil. This oil was dissolved in methanol and was filtered on dicalite; 0.4 ml of HCl 1N and water were added. The mixture was concentrated under reduced pressure, lyophilized and dried under high vacuum at 50° C., affording 0.087 g (14%) of a white powder as the hydrated (3/2 H₂O) dihydrochloride of N-[(2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetyl]-methanesulfonamide (compound 305).

Analysis for hydrated (3/2 H₂O) dihydrochloride of compound 305:

¹H-NMR (DMSO): 7.92 (s, 1H), 7.81 (s, 2H), 7.35 (m, 5H), 4.66 (s, 2H), 4.08 (m, 3H), 4.0-3.9 (m, 2H), 3.75 (t, 2H), 3.4-3.2 (m, 6H), 3.2 (s, 3H), 3.1-2.8 (m, 4H).

Mass (LC/MS APCI+): 612 (MH+).

1.4.6.2. N-[(2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetyl]-benzenesulfonamide (compound 306).

In a round-bottomed flask fitted with a reflux condenser and a thermometer was introduced (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic acid (compound 235 prepared at example 1.4.2; 2.7 g, 4.54 mmoles) dissolved in CH₂Cl₂ (25 ml). Benzenesulphonamide (1.07 g, 6.8 mmoles), DMAP (10 mg, 0.45 mmoles) and EDCI (0.96 g, 5 mmoles) were added to the solution and the reaction mixture was stirred at room temperature for 48 hours. The organic solution was washed with HCl 0.1N and brine, dried over MgSO₄ and concentrated. The residue was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/NH₃: 95/5/0.2 v/v/v) to afford the monohydrate of N-[(2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetyl]-benzenesulfonamide (compound 306; 1.5 g, 50%) as a beige solid.

Analysis for the monohydrate of compound 306:

¹H-NMR (DMSO): 7.85 (s, 1H), 7.72 (s, 2H), 7.68 (dd, 2H), 7.4-7.25 (m, 8H), 4.64 (s, 2H), 4.05-3.75 (m, 2H), 3.76 (s, 2H), 3.7-3.6 (m, 3H), 3.2-3.0 (m, 6H), 2.8-2.55 (m, 4H).

Mass: (LC/MS APCI+): 674 (MH+).

1.4.7. Preparation of compounds of formula I according to process (a.7).

N-p-toluenesulfonic-carbamic acid 2-{4-[2-(3,5-bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethyl ester (compound 307).

In a round-bottomed flask fitted with a reflux condenser and a thermometer was introduced compound 2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethanol (compound 157 prepared at example 1.4.1; 0.5 g, 0.99 mmoles) dissolved in CH₂Cl₂ (5 ml). p-toluenesulfonylisocyanate (0.14 ml, 1.09 mmoles) was added to the solution and the reaction mixture was stirred at room temperature. The organic solution was washed with NaHCO₃ and the aqueous layer was extracted with CH₂Cl₂. The combined organic layers were dried over MgSO₄ and concentrated. The residue was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/NH₃: 95/5/0.2) to give N-p-toluenesulfonic-carbamic acid 2-{4-[2-(3,5-bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethyl ester (compound 307; 400 mg, 60%) which was converted into its dihydrochloride salt by reaction with HCl in diethylether (Friesen R. W. and Phipps L. G., Synlett (1991), 420-422).

Analysis for the dihydrochloride of compound 307:

¹H-NMR (DMSO): 7.91 (s, 1H), 7.82 (s, 2H), 7.74 (d, 2H), 7.4 (m, 5H), 7.38 (d, 2H), 4.67 (s, 2H), 4.24 (m, 3H), 4-3.9 (m, 1H), 3.3-3.05 (m, 8H), 3.05-2.9 (m, 2H), 2.33 (s, 3H).

Mass: (LC/MS APCI+): 674 (MH+).

-   -   1.4.8. Preparation of compounds of formula I according to         process (a.8).

N-(3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-1-phenyl-propyl)-acetamide (compound 308).

In a round-bottomed flask fitted with a reflux condenser and a thermometer, 1.55 g (2.73 mmoles) of 3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-1-phenyl-propan-1-ol (compound 169 prepared at example 1.4.1 above) and 3.6 ml of acetonitrile were introduced. The mixture was cooled to 0° C. and 3 ml of H₂SO₄ 12N were added dropwise. The reaction was stirred at room temperature for 4 hours. Cold water was added and a solution of NaOH 6N was added until pH 7. The mixture was filtered, and extracted with CH₂Cl₂. The organic phase was dried over magnesium sulfate, and concentrated under reduced pressure, affording 1.41 g of crude product. Purification by chromatography on silica gel (eluent: CH₂Cl₂/CH₃OH/NH₄OH, 97/3/03, (v/v/v)) gave 1.1 g of an oil which was dissolved in 10 ml of diisopropylether; 1.75 ml of a solution 1.88N of HCl in ether was added affording, after filtration, 0.82 g of the hydrated (5/4 H₂O) dihydrochloride of N-(3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-1-phenyl-propyl)-acetamide (compound 308) as a white powder.

Analysis for the hydrated (5/4 H₂O) dihydrochloride of compound 308

¹H-NMR (DMSO): 8.43 (d, 1H), 7.93 (s, 1H), 7.5-7.3 (m, 5H), 7.3-7.15 (m, 5H), 4.83 (t, 1H), 4.7 (s, 2H), 4.4 (t, 1H), 4.1 (dd, 1H), 3.95 (dd, 1H), 3.5-3.0 (m, 10H), 2.05 (m, 2H), 1.86 (s, 3H).

Mass: (LC/MS APCI+): 608 (MH+).

1.4.9. Preparation of compounds of formula I according to process (a.9).

a. Following the procedure described in Maryanoff B. E. et al., J. Med Chem. (1981), 24 (1), 79-88: cis- and trans-4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic acid ethyl ester (compounds 310 and 311).

In a round-bottomed flask fitted with a reflux condenser and a thermometer was introduced 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazine (compound 86 prepared at example 1.3.1 above; 2.5 g, 5.8 mmol) dissolved in MeOH (30 ml). Acetic acid (0.43 ml, 7.52 mmoles), ethyl-4-oxocyclohexanecarboxylate (3.7 ml, 23 mmoles) and NaBH₃CN (0.55 g, 8.7 mmoles) were added to the solution and the reaction mixture was heated at 50° C. MeOH was evaporated in vacuo and the residue was taken up in water. The aqueous layer was extracted with CH₂Cl₂ and the combined organic layers were dried over MgSO₄ and concentrated. The crude was purified by chromatography on silica gel (eluent:Hex/AcOEt: 30/70 v/v) to give cis- and trans-4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic acid ethyl ester (compound 309; 3 g, 88%), which was separated by chiral HPLC (Chiralpak AD, eluent: MeOH/EtOH/Benzine/DEA: 8/2/90/0.1 v/v/v/v) into its cis and trans isomers (compounds 310 and 311). It was impossible by NMR to determine which of these two compounds has the cis-conformation and which has the trans-configuration.

b. Cis- and trans-4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic acid dichlorhydrate (compounds 312 and 313).

In a round-bottomed flask fitted with a reflux condenser and a thermometer were introduced cis- or trans-4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic acid ethyl ester (compound 310 prepared at example 1.4.9; 0.9 g, 1.53 mmoles), HCl 1N (8 ml) and the solution was added at reflux overnight. The pH of the solution was adjusted to 5-6 by addition of aqueous NaOH and was extracted with AcOEt. The combined organic layers were dried over MgSO₄ and concentrated. The crude was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/NH₃: 90/10/0.5 then 85/15/1 v/v/v) to afford cis- or trans-4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic acid (compounds 312 or 313) as a pale yellow solid (0.4 g, 50%) which was converted into the dihydrochloride salt by reaction with HCl in diethylether. It was impossible by NMR to determine which of these two compounds has the cis-conformation and which has the trans-configuration.

Analysis for the dihydrochloride of compound 312:

¹H-NMR (DMSO): 8.01 (s, 1H), 7.93 (s, 2H), 7.53 (m, 2H), 7.43 (m, 3H), 4.73 (dd, 2H), 4.64 (t, 1H), 4.16 (dd, 1H), 3.99 (dd,1H), 3.77 (m, 2H), 3.56 (m, 2H), 3.46 (m, 2H), 3.24 (m, 1H), 3.13 (m, 2H), 2.18 (m, 1H), 2.01 (m, 1H), 1.99 (m, 1H), 1.44 (m, 1H), 1.33 (m, 1H).

Mass: (LC/MS APCI+): 559 (MH+).

Analysis for the dihydrochloride of compound 313:

¹H-NMR (DMSO): 8.0 (s, 1H), 7.88 (s, 2H), 7.42 (m, 5H), 4.70 (dd, 2H), 4.33 (t, 1H), 4.00 (dd, 1H), 3.92 (dd,1H), 3.54 (m, 2H), 3.21 (m, 2H), 3.17 (m, 1H), 2.84 (m, 2H), 2.74 (m, 2H), 2.58 (m, 1H), 2.06 (m, 1H), 1.92 (m, 1H), 1.51 (m, 1H), 1.37 (m, 1H).

Mass: (LC/MS APCI+): 559 (MH+).

1.4.10. Preparation of compounds of formula I according to process (a.10).

-   6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic     acid (2,4-dimethoxy-benzyloxy)-amide (Compound 314).

In a round-bottomed flask, 0.85 g (1.55 mmoles) of 6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic acid (compound 234), 0.28 g (2.02 mmoles) of hydroxybenzotriazole, 0.427 g (2.33 mmoles) of 2,4-dimethoxy-benzylhydroxylamine (obtained as described in B. Barlaam, A. Hamon, M. Maudet, Tetrahedron Lett (1998), 39, 7865-7868) and 0.456 g (2.33 mmoles) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, were introduced. The mixture was stirred at room temperature for 21 hours. The mixture was diluted with 40 ml of EtOAc and washed with water, saturated sodium bicarbonate, brine, dried over magnesium sulfate and concentrated under reduced pressure affording 1.27 g of crude product. Purification by chromatography on silica gel (eluent: ethylacetate/CH₃OH 94/6) gave 71% of 6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic acid (2,4-dimethoxy-benzyloxy)-amide (compound 314).

Analysis for compound 314:

¹H-NMR (DMSO): 7.94 (s, 1H), 7.84 (s, 2H), 7.2 (m, 6H), 6.5 (m, 2H), 4.68 (s, 2H), 4.64 (s, 2H), 3.89 (m, 1H), 3.75 (m, 7H), 3.6 (m, 1H), 2.45-2.2 (m,9H), 2.12 (t, 2H), 1.88 (t, 2H), 1.45 (m, 2H), 1.33 (m, 2H), 1.23 (m, 2H).

Mass: (LC/MS APCI+): 712 (MH+)

-   6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic     acid hydroxyamide (compound 315) is prepared by deprotection of the     O-protected hydroxamate 314 by trifluoroacetic acid:

In a round-bottomed flask fitted with a reflux condenser and a thermometer, 0.97 g (1.36 mmoles) of 6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic acid (2,4-dimethoxy-benzyloxy)-amide (compound 314) in 10 ml 5% TFA-dichloromethane solution, was stirred at room temperature during one day. Again, 1 ml of TFA was added. The reaction mixture turned deep purple. The mixture was evaporated in vacuum, diluted in CH₃OH and filtered to remove insoluble material. Evaporation of the filtrate gave 1.17 g of a brown oil which was purified by chromatography on silica gel affording 0.21 g of 6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic acid hydroxyamide (compound 315) transformed to its dimaleate salt by adding 0.085 g of maleic acid.

Analysis for monohydrated dimaleate of compound 315:

¹H-NMR (DMSO): 7.96 (s,1H), 7.86 (s, 2H), 7.3 (m, 5H), 6.11 (s, 4H), 4.67 (s,2H), 3.9-3.8 (m, 3H), 3.5-2.6 (m, 10H), 1.94 (s, 2H), 1.6-1.4 (m, 4H), 1.25 (m, 2H).

Mass: (LC/MS APCI+): 562 (MH+)

EXAMPLE 2 Preparation of Compounds of Formula I According to Process (b)

4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-methoxycarbonylmethyl-piperazin-1-yl)-ethyl]-benzoic acid methyl ester (compound 316).

Following the method described in Lin C.-H. et al., J. Med. Chem. (1993), 36, 2208-2218:

In a round-bottomed flask fitted with a reflux condenser and a thermometer were introduced {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-bromo-phenyl)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 184 prepared at example 1.4.1 above; 0.5 g, 0.8 mmoles), Et₃N (0.26 ml, 1.8 mmoles), MeOH (3 ml) and DMF (9 ml). The mixture was purged with N₂ and a stream of CO was passed into the mixture for 10 min. A solution of Pd(OAc)₂ (19.2 mg, 10% moles) and Diphenylphosphinopropane (Dppp) (33 mg, 10% moles) dissolved in MeOH/DMF 1/3 (0.65 ml), purged with N₂, was then added to the mixture. The reaction mixture was heated at 70° C. and CO was bubbled through the reaction mixture overnight. The reaction mixture was purged with N₂, quenched with NaHCO₃ and extracted with AcOEt. The combined organic layers were dried over MgSO₄ and concentrated to give an oil which was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/NH₃: 99.5/0.5/0.1 v/v/v) to afford 4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-methoxycarbonylmethyl-piperazin-1-yl)-ethyl]-benzoic acid methyl ester (compound 316; 150 mg, 30%).

Analysis for compound 316:

¹H-NMR (DMSO): 7.95 (s, 2H), 7.90 (s, 1H), 7.75 (d, 2H), 7.45 (d, 2H), 4.65 (s, 2H), 4.0-3.65 (m, 3H), 3.90 (s, 3H), 3.60 (s, 3H), 3.15 (s, 2H), 2.60-2.30 (m, 8H).

EXAMPLE 3 Preparation of Compounds of Formula I According to Process (c)

{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 317).

Following the method described in Tschaen D. M. et al., JOC (1995), 60, 4324-4330:

A round-bottomed flask charged with Pd(OAc)₂ (36 mg, 4% moles) and P(o-tol)3 (192 mg, 20% mol) was evacuated and then vented to nitrogen. N-methylpyrrolydone (NMP) (4 ml) was added and the mixture was heated at 50° C. for 30 min. Diethylzinc in hexane (0.29 ml) was added and the mixture was maintained at 50° C. for an additional 30 min. The mixture was cannulated into a flask containing a solution of {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-bromo-phenyl)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 184 prepared at example 1.4.1 above; 2.33 g, 4.0 mmoles) and Zn(CN)₂ (0.47 g, 4.0 mmoles) dissolved in NMP (6 ml). The reaction mixture was heated at 60° C. for 3 hours. The eluent was evaporated and the residue was taken up in diethylether. The precipitate was filtered and the organic solution was washed with ammonium hydroxyde, dried over MgSO₄ and concentrated. The residue was purified by chromatography on silica gel (eluent: Hex/AcOEt: 75/25 v/v) to give {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 317; 0.9 g, 34%).

Analysis for compound 317:

¹H-NMR (DMSO): 7.95 (s, 1H), 7.85-7.75 (m, 4H), 7.50 (d, 2H), 4.65 (s, 2H), 3.95-3.65 (m, 3H), 3.60 (s, 3H), 3.15 (s, 2H), 2.60-2.30 (m, 8H).

Mass: (LC/MS APCI+): 530(MH+)

EXAMPLE 4 Preparation of Compounds of Formula I According to Process (d)

4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carboxymethyl-piperazin-1-yl)-ethyl]-benzoic acid methyl ester hemihydrate (compound 318).

In a round-bottomed flask was introduced 4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-methoxycarbonylmethyl-piperazin-1-yl)-ethyl]-benzoic acid methyl ester (compound 316 prepared at example 2 above; 2.17 g, 3.86 mmoles) dissolved in MeOH (30 ml). To this solution cooled at 0° C. was added KOH (0.54 g, 9.62 mmoles) dissolved in MeOH (20 ml). The reaction mixture was allowed to stand at room temperature overnight. The reaction was cooled to 0° C., quenched by addition of HCl 0.1 N and extracted with CH₂Cl₂. The combined organic layers were dried over MgSO₄ and concentrated. The residu was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/H₂O: 95/5/0.5) to yield 4-[2-(3,5-bis-trifluoromethyl-benzyloxy)-1-(4-carboxymethyl-piperazin-1-yl)-ethyl]-benzoic acid methyl ester hemihydrate (compound 318; 1.5 g, 71%).

Analysis for the hemihydrate of compound 318:

¹H-NMR (DMSO): 7.93 (s, 1H), 7.90 (d, 2H), 7.79 (s, 2H), 7.47 (d, 2H), 4.65 (s, 2H), 3.95-3.7 (m, 2H), 3.85 (s, 3H), 3.72 (t, 1H), 3.08 (s, 2H), 2.65-2.45 (m, 8H).

Mass: (LC/MS APCI+): 549 (MH+).

4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carboxymethyl-piperazin-1-yl)-ethyl]-benzoic acid hemihydrate (compound 319).

In a round-bottomed flask were introduced 4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-methoxycarbonylmethyl-piperazin-1-yl)-ethyl]-benzoic acid methyl ester (compound 316 prepared at example 2; 2 g, 3.56 mmoles), KOH (0.4 g, 7.12 mmoles) and MeOH. The reaction mixture was heated at 60° C. for 6 hours. MeOH was removed under reduce pressure and the residue was taken up by water. The pH was adjusted to 3-4 and the solution was extracted with AcOEt. The organic combined layers were dried over MgSO₄ and concentrated. The residue was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/H₂O: 90/10/1 v/v/v) to give 4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carboxymethyl-piperazin-1-yl)-ethyl]-benzoic acid hemihydrate (compound 319; 0.88 g, 45%).

Analysis for the hemihydrate of compound 319:

¹H-NMR (DMSO): 7.93 (s, 1H), 7.90 (d, 2H), 7.81 (s, 2H), 7.43 (d, 2H), 4.65 (s, 2H), 3.85 (dd, 1H), 3.8 (dd, 1H), 3.72 (t, 1H), 3.09 (s, 2H), 2.65-2.45 (m, 8H).

Mass: (LC/MS APCI+): 535 (MH+).

{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carbamoyl-phenyl)-ethyl]-piperazin-1-yl}-acetic acid (compound 321) and 4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carbamoylmethyl-piperazin-1-yl)-ethyl]-benzamide (compound 322).

In a small autoclave, 1.5 g (2.73 mmoles) of 4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carboxymethyl-piperazin-1-yl)-ethyl]-benzoic acid methyl ester (compound 318) were dissolved in methanol. The solution was saturated with NH3 and heated at 100° C. for three days. Methanol was then evaporated and the crude product was purified by chromatography (eluent: CH₂Cl₂/MeOH/NH₃: 80/20/0.5 v/v/v) to give 880 mg of {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carbamoyl-phenyl)-ethyl]-piperazin-1-yl}-acetic acid (compound 321) as a grey solid. 4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-carbamoylmethyl-piperazin-1-yl)-ethyl]-benzamide (compound 322) was isolated as a side product (150 mg).

Analysis for compound 321:

¹H-NMR (DMSO): 7.95 (s, 1H), 7.85-7.8 (m, 5H), 7.38 (d, 2H), 7.2 (s, 1H), 4.66 (s, 2H), 3.95-3.6 (m, 3H), 3.02 (s, 2H), 2.65-2.35 (m, 8H).

Mass: (LC/MS APCI+): 534 (MH+).

Analysis for compound 322:

¹H-NMR (DMSO): 7.96 (s, 1H), 7.85 (s+d, 3H), 7.37 (d, 2H), 7.2 (s, 1H), 7.0-6.9 (s+s, 2H), 4.67 (s, 2H), 3.92 (dd, 1H), 3.82 (dd, 1H), 3.71 (t, 1H), 2.79 (s, 2H), 2.55-2.35 (m, 8H).

Mass: (LC/MS APCI+): 533 (MH+).

EXAMPLE 5 Preparation of Compounds of Formula I According to Process (f)

Dihydrochloride of {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic acid (compound 320).

In a round-bottomed flask were introduced compound {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 317 prepared at example 2; 0.9 g, 1.7 mmoles), KOH (0.24 g, 4.25 mmoles) and MeOH. The reaction mixture was stirred at room temperature overnight. The reaction mixture was diluted with water and the pH was adjusted to 3. The solution was extracted with CH₂Cl₂ and the combined organic layers were dried over Na₂SO₄ and concentrated. The residue was crystallized from diethylether/HCl to give the dihydrochloride of {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic acid (compound 320; 0.8 g, 80%).

Analysis for the dihydrochloride of compound 320:

¹H-NMR (DMSO): 7.86 (s, 1H), 7.71 (d, 2H), 7.62 (s, 2H), 7.52 (d, 2H), 4.58 (s, 2H), 4.1-3.8 (m, 3H), 3.72 (s, 2H), 3.35-3.15 (m, 4H), 2.9-2.4 (m, 4H).

Mass: (LC/MS APCI+): 516 (MH+).

EXAMPLE 6 Preparation of Compounds of Formula I According to Process (g)

{4-[1-(2-Amino-phenyl)-2-(3,5-bis-trifluoromethyl-benzyloxy)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 323)

In a round-bottomed flask fitted with a reflux condenser and a thermometer were introduced {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2-nitro-phenyl)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 190 prepared at example 1.4.1 above; 2 g, 3.64 mmoles), SnCl₂ (3.45 g, 18.2 mmoles) and MeOH (40 ml) and the reaction mixture was heated at 60° C. for 3 hours. MeOH was evaporated in vacuo and the crude was taken up in water. The pH was adjusted to 8-9 by addition of aqueous NaOH and the solution was extracted with AcOEt. The combined organic phases were dried over MgSO₄ and concentrated. The resulting oil was purified by chromatography on silica gel (eluent: CH₂Cl₂/MeOH/NH₃: 99/1/0.1 v/v/v) to yield {4-[1-(2-Amino-phenyl)-2-(3,5-bis-trifluoromethyl-benzyloxy)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 323; 1.7 g, 90%) as a yellow oil.

Analysis for compound 323:

¹H-NMR (DMSO): 7.95 (s, 1H), 7.90 (s, 2H), 6.95 (t, 1H), 6.55-6.45 (m, 3H), 4.90 (s, NH2), 4.65 (s, 2H), 3.85 (dd, 1H), 3.65 (dd, 1H), 3.40 (t, 1H), 3.15 (s, 2H), 2.55-2.35 (m, 8H).

Mass: (LC/MS APCI+): 520 (MH+).

{4-[1-(2-Amino-phenyl)-2-(3,5-bis-trifluoromethyl-benzyloxy)-ethyl]-piperazin-1-yl}-acetic acid (compound 324)

In a round-bottomed flask were introduced {4-[1-(2-Amino-phenyl)-2-(3,5-bis-trifluoromethyl-benzyloxy)-ethyl]-piperazin-1-yl}-acetic acid methyl ester (compound 323; 1.3 g, 2.5 mmoles), KOH (0.35 g, 6.3 mmoles) and MeOH (20 ml). The reaction mixture was stirred at room temperature for 6 hours. MeOH was removed under reduce pressure and the residue was taken up in water. The pH was adjusted to 6 and the solution was extracted with CH₂Cl₂. The combined organic layers were dried over MgSO₄ and concentrated. The residue (1.1 g, 88%) was recrystallized from diethylether to give {4-[1-(2-Amino-phenyl)-2-(3,5-bis-trifluoromethyl-benzyloxy)-ethyl]-piperazin-1-yl}-acetic acid (compound 324; 0.75 g, 60%) as white needles.

Analysis for compound 324:

¹H-NMR (DMSO): 7.89 (s, 1H), 7.82 (s, 2H), 6.97 (t, 1H), 6.55-6.4 (m, 3H), 4.6 (dd, 2H), 3.85 (dd, 1H), 3.68 (dd, 1H), 3.52 (t, 1H), 3.34 (s, 2H), 3.2-3.0 (m, 4H), 2.8-2.5 (m, 4H).

Mass: (LC/MS APCI+): 506 (MH+).

Another aspect of the invention concerns the use of a therapeutically effective amount of an α-arylethylpiperazine derivative of formula I, an individual enantiomer, diastereoisomer or non-toxic pharmaceutically acceptable salt thereof for the prevention and/or treatment of a condition associated with pathological levels of substance P in a patient.

As used herein, “pathological levels of substance P” means a level of substance P sufficient to cause a pathological process leading to pain, emesis, pulmonary diseases such as asthma and bronchitis or allergic rhinitis. In a preferred embodiment, the present invention concerns the use of a therapeutically effective amount of an α-arylethylpiperazine derivative of formula I, an individual enantiomer, diastereoisomer or non-toxic pharmaceutically acceptable salt thereof for the prevention and/or treatment of asthma and/or allergic rhinitis.

As used herein, “patient” means any living animal in need of prevention and/or treatment of symptoms associated with pathological levels of substance P. Such patients include most preferably humans.

As used herein, “a therapeutically effective amount” of an α-arylethylpiperazine derivative of formula I an amount sufficient to at least ameliorate or prevent the symptoms of the patients. This amount may vary within wide limits depending on a series of factors such as the age and sex of the patient, the state of condition being treated, the overall health of the patient, the method of administration, the severity of side-effects and the like.

Preferably, the daily dosage is administered once or several times, depending on factors such as the severity of the condition, the mode of administration, the tolerance by the patient.

Accordingly, a further aspect of the invention concerns a pharmaceutical composition comprising a therapeutically effective amount of an α-arylethylpiperazine derivative of formula I, an individual enantiomer, diastereoisomer or non-toxic pharmaceutically acceptable salt thereof, as well as pharmaceutically acceptable solid or liquid excipients or carriers therefor.

Suitable pharmaceutically acceptable excipient or carriers are the ones well known by the person skilled in the art and are prepared according to the methods generally applied by pharmacists, and may include solid, liquid or gazeous, non-toxic pharmaceutically acceptable vehicles. The percentage of active compound/pharmaceutically acceptable carrier may vary within very large ranges, only limited by the tolerance and the possible side-effects upon the patient. The limits are particularly determined by their frequency of administration.

For preparing solid compositions such as tablets, the compound according to the invention is mixed with conventional tabletting ingredients such as corn starch, lactose, sucrose, sorbitol, talc, stearic acid, magnesium stearate, dicalcium phosphate, gum. Solid formulations may also include sustained release excipients such as cellulose ester derivatives or any other known matricial excipient. Tablet formation by wet or dry granulation may take place according to the methods well known by pharmacists.

Liquid formulations include syrups, aqueous or oil suspensions, flavoured emulsions . . . . Compositions for inhalation include solutions and suspensions in pharmaceutically aqueous or organic solvents or powders, suitable for oral or nasal administration.

As indicated above, the α-arylethylpiperazine derivatives of formula I, their individual enantiomers, diastereisomers and pharmaceutically acceptable salts thereof have the property of acting as neurokinin antagonists, without interacting with calcium channels. These advantageous properties are demonstrated by the following studies.

-   1. Characterisation of the interactions between a test substance and     the human recombinant NK₁ receptor.

Tachykinin receptors are divided into three subclasses: NK₁, NK₂ and NK₃ receptors. NK₁ receptors are found on sensory nerve terminals, on smooth muscles and on immune cells. Their activation by substance P is involved in several pathophysiological states including, but not restricted to, asthma (mucus secretion, bronchoconstriction, plasma extravasation . . . ), emesis and nociception (Bertrand and Geppetti, TIPS (1996), 17, 255-259; Longmore et al. DN&P (1995), 1, 1-23).

The recombinant human NK₁ receptor is coded by a gene located on chromosome 2 (Gerard N. et al., Biochemistry (1991), 30, 10640-10646.). Besides being more ethical, the use of human cloned receptors offers the advantage of population homogeneity (avoidance of cross binding of the test substances, including the radioligand, with other receptors or other receptor subtypes) and of being cloned from the target species i.e. human.

NK₁ receptors may be studied with [4,53H-Leu10] substance P, a commercially available radioligand. It offers a good selectivity, a high affinity and a low non specific binding (Aharony et al., The Journal of Pharmacology and Experimental Therapeutics (1991), 259, 146-155).

The following test was designed to assess the affinity of test substances for human recombinant NK₁ receptors expressed in Chinese Hamster Ovarian (CHO) cells.

1.1. Cells

CHO cells expressing the human recombinant NK₁ receptor are used. The cells were obtained from Euroscreen (Brussels, Belgium).

Cells expressing the human NK₁ receptor are routinely cultured in 175 cm2 flasks containing 75 ml of medium F12 (Ham) enriched with 2 mmol/l L-glutamine, 100 IU/ml penicilline, 100 μg/ml streptomycine, 1% sodium pyruvate, 2.5 μg/ml fungizone amphotericin B, 400 μg/ml geneticin and supplemented with 10% foetal calf serum. The cells are grown at 37° C. in a humidified atmosphere composed of 5% CO2 and 95% air. When subcultured, the cells are seeded at a concentration of 50,000 cells/cm2.

1.2. Experimental Procedure

-   -   1.2.1. Membrane Preparation

Confluent cells are gently scraped and resuspended in 25 ml of phosphate buffered saline without calcium and magnesium. The cellular suspension is centrifuged at 1500×g for 3 min (4° C.). The cell pellet is homogenized in a 15 mmol/l Tris-HCl (pH 7.5) buffer, 2 mmol/l MgCl₂, 0.3 mmol/l EDTA, 1 mmol/l EGTA. The crude membrane fraction is collected by two consecutive centrifugation steps at 40,000×g for 25 min (4° C.). The final pellet is resuspended in 20 mmol/l Tris-HCl (pH 7.4), 250 mmol/l sucrose buffer at a protein concentration ranging from 2 to 6 mg/ml and stored in liquid nitrogen.

-   -   1.2.2. Test Design

The inhibition constant (Ki) is determined using increasing concentrations of the test substance. The concentration range usually encompasses 6 log units with variable steps (0.3 to 1 log). Assays are performed in mono- or duplicate.

Membranes are incubated at 25° C. for 60 min in 0.5 ml of a 50 mmol/l Tris-HCl buffer (pH 7.4) containing 2 mmol/l MgCl₂, 100 μg/ml bacitracine, 0.1 to 0.4×10⁻⁹ mol/l of [4,5³H-Leu¹⁰] substance P (specific activity>100 Ci/mmol) and increasing concentrations of the test substance. The non specific binding (NSB) is defined as the residual binding observed in the presence of a concentration in excess of reference substance (e.g. 10⁻⁶ mol/l CP-96,345). Membrane-bound and free radioligands are separated by rapid filtration through glass fiber filters (equivalent to Whatman GF/C or GF/B; VEL, Belgium) presoaked in 0.1% polyethyleneimine to reduce non specific binding. Samples and filters are rinsed by at least 6 ml of 50 mmol/l Tris-HCl (pH 7.4) buffer. The entire filtration procedure does not exceed 10 seconds per sample. The radioactivity trapped onto the filters is counted by liquid scintillation in a β-counter (Tri-Carb 1900 or TopCount 9206, Camberra Packard, Belgium, or any other equivalent counter).

1.3. Data Analysis

Data analysis is performed by a computerized non linear (NLIN) curve fitting method using a set of equations describing several binding models assuming populations of independent non-interacting receptors which obey to the law of mass action (Weiland, G. A. and P. B. Molinoff, Life Science (1981), 29, 313-330; Molinoff P. et al., Life Science (1981), 29, 427-443). Initial values for the different variables may be provided by the experimenter.

1.4. Results

Table A below summarizes the results obtained with the compounds according to the invention. In this Table, pIC₅₀=−log IC₅₀, IC₅₀ being the concentration of compound necessary to inhibit by 50% the specific binding of [4,5³H] substance P.

TABLE A Binding of compounds of formula I to NK₁ receptors Cpd No. Free base/Salt pIC₅₀ 136 2 maleate 7.1 138 2 maleate 8.0 139 2 maleate 8.2 141 2 maleate 8.1 142 2 maleate 8.1 143 2 HCl 7.4 144 2 HCl 7.4 145 2 HCl 7.5 146 1 HCl 7.8 147 2 HCl.2 H₂O 8.0 148 2 maleate.½H₂O 7.4 149 2 maleate.½H₂O 7.2 150 2 maleate 8.3 151 2 maleate 7.7 152 2 maleate 7.9 155 2 maleate 7.8 156 2 maleate 8.1 157 2 HCl.½H₂O 8.2 158 2 maleate 8.1 160 2 HCl 7.5 161 3 HCl 8.1 162 3 HCl 8.1 164 2 maleate 7.4 170 3 HCl.½H₂O 7.3 171 — 7.1 173 2 HCl 7.6 174 2 HCl 7.4 175 2 HCl.1 H₂O 8.3 176 2 HCl 7.6 177 2 HCl 8.2 182 2 maleate 7.0 191 2 HCl 7.2 208 2 maleate 7.2 219 2 maleate 9.5 227 2 maleate 7.4 229 2 HCl 7.1 230 2 HCl.½H₂O 7.3 231 2 HCl.1 H₂O 7.1 232 2 maleate 7.3 233 2 HCl 7.5 234 {fraction (3/2)}maleate 7.8 235 2 maleate 7.2 236 2 maleate 7.1 237 2 maleate 7.0 239 2 HCl 7.5 241 2 HCl.1 H₂O 8.1 242 2 HCl.½H₂O 8.1 243 2 maleate.½H₂O 7.2 244 — 7.4 245 1 H₂O 7.2 246 2 maleate 7.1 248 2 maleate 7.6 249 2 maleate 7.5 250 2 HCl 7.1 251 1 H₂O 8.1 252 1 H₂O 7.7 253 2 maleate 7.2 254 ½H₂O 7.3 255 2 HCl 7.1 265 2 HCl 7.1 269 2 maleate 7.0 271 1 maleate.1 H₂O 7.4 273 2 HCl.3 H₂O 8.5 274 2 HCl.1 H₂O 7.9 275 2 HCl.5/2 H₂O 8.4 277 2 HCl.1 H₂O 8.0 279 2 HCl.1 H₂O 8.7 281 2 HCl.½H₂O 8.1 283 2 HCl.{fraction (3/2)}H₂O 7.6 284 2 maleate.1 H₂O 7.3 285 2 maleate.1 H₂O 7.3 287 2 HCl.1 H₂O 7.5Cpd No. 288 2 maleate.½H2O 8.3 289 2 HCl 8.5 291 2 HCl 7.6 292 2 maleate 7.8 293 2 maleate 7.2 294 2 maleate 7.9 295 — 7.2 297 2 HCl 7.7 298 2 HCl 7.8 299 2 HCl 7.8 300 2 HCl 7.5 301 2 HCl.⅓C₃H₈O 7.8 302 2 HCl 8.4 303 2 HCl 8.3 304 2 maleate 8.1 305 2 HCl.{fraction (3/2)}H₂O 7.1 306 1 H₂O 7.5 307 2 HCl 7.8 308 2 HCl.{fraction (5/4)}H₂O 7.9 312 2 HCl 7.6 313 2 HCl 7.8 315 2 maleate.1 H₂O 8.3 320 2 HCl 7.0

-   2. Characterization of the interactions between a test substance and     the verapamil binding site of the L-type calcium channel.

2.1. Membrane Preparation

200-250 g male Sprague-Dawley rats are sacrificed by decapitation. Cerebral cortices are quickly dissected on ice and homogenized in a 20 mmol/l Tris-HCl (pH 7.4) buffer containing 250 mmol/l sucrose (buffer A). The homogenate is centrifuged at 30,000 g for 15 min at 4° C. The resulting crude membrane pellet is resuspended in a 50 mmol/l Tris-HCl (pH 7.4) buffer and incubated 15 min at 37° C. before being centrifuged at 30,000×g for 15 min at 4° C. After two more washes under the same conditions, the final pellet is resuspended in buffer A at a protein concentration ranging from 15 to 25 mg/ml and stored in liquid nitrogen.

2.2. Binding Experiments

Binding experiments are essentially performed according to Reynolds J. et al., J. Pharmacol. Exp. Ther. (1986), 237, 731-738. (1986) with slight modifications.

Membranes (120-175 μg/assay) are incubated at 25° C. for 60 min in 0.5 ml of a 50 mmol/l Tris-HCl buffer (pH 7.4) containing 2 mmol/l MgCl₂, 0.2 to 0.4×10-9 mol/l of [³H]D888 (85 Ci/mmol; Amersham, Belgium) and 10 μmol/l of the test substance. The non specific binding (NSB) is defined as the residual binding observed in the presence 10 μM verapamil. Membrane-bound and -free radioligands are separated by rapid filtration through glass fiber filters (equivalent to Whatman GF/C or GF/B; VEL, Belgium) presoaked in 0.1% polyethyleneimine to reduce non specific binding. Samples and filters are rinsed by at least 6 ml of 50 mmol/l Tris-HCl (pH 7.4) buffer. The entire filtration procedure does not exceed 10 seconds per sample. The radioactivity trapped onto the filters is counted by liquid scintillation in a β-counter.

2.3. Data Analysis

The inhibition of the radioligand specific binding is calculated as follows: ${\%\quad{inhibition}} = {100 - \left( {\frac{B_{I} - B_{NS}}{B_{O} - B_{NS}} \times 100} \right)}$

-   -   where B_(I) and B_(o) represent the binding observed in the         presence and absence of the test substance respectively; and         -   B_(NS) is the non specific binding.

Data analysis is performed by a computerized non linear curve fitting method using a set of equations describing several binding models assuming competitive interactions between ligands (Weiland G. A. and P. B. Molinoff Life Science (1981), 29, 313-330; Molinoff P. et al. (1981) Life Sci., 29, 427-443).

2.4. Results

Table B below summarizes the results obtained with the compounds according to the invention.

TABLE B Inhibition of [³H]D888 binding to the verapamil binding site of the L-type calcium channel by 10 μmol/l of test subtances. Cpd No. Free base /Salt % inhibition* 160 2 HCl 0 229 2 HCl 0 230 2 HCl.½H₂O 0 231 2 HCl, 1 H₂O 0 232 2 maleate + 233 2 HCl 0 234 {fraction (3/2)}maleate 0 235 2 maleate 0 236 2 maleate 0 237 2 maleate 0 239 2 HCl 0 241 2 HCl.1 H₂O + 242 2 HCl.½H₂O + 243 2 maleate.½H₂O 0 244 −+ 245 1 H₂O 0 246 2 maleate + 248 2 maleate + 249 2 maleate + 250 2 HCl + 251 1 H₂O + 252 1 H₂O + 253 2 maleate 0 254 ½H₂O 0 255 2 HCl 0 265 2 HCl 0 269 2 maleate 0 271 1 maleate.1 H₂O + 273 2 HCl.3 H₂O 0 274 2 HCl.1 H₂O 0 275 2 HCl.{fraction (5/2)}H₂O 0 277 2 HCl.1 H₂O 0 279 2 HCl.1 H₂O 0 281 2 HCl.½H₂O + 283 2 HCl.{fraction (3/2)}H₂O + 285 2 maleate.1 H₂O + 287 2 HCl.1 H₂O + 291 2 HCl 0 292 2 maleate + 295 − + 297 2 HCl + 298 2 HCl + 299 2 HCl + 300 2 HCl + 301 2 HCl.⅓C₃H₈O + 302 2 HCl + 303 2 HCl + 304 2 maleate + 305 2 HCl.{fraction (3/2)}H₂O 0 306 1 H₂O + 307 2 HCl + 312 2 HCl 0 313 2 HCl 0 320 2 HCl 0 *0: inhibition < 20%; +: inhibition comprised between 20 and 50% Cpd = compound.

-   3. Effect of compound on isolated rat aorta contracted by 100 mM     KCl.

Rat thoracic aorta depolarized by 100 mM KCl develops a contraction induced by an influx of Ca²⁺ into the smooth muscle cell. An inhibition of this contraction could predict a Ca²⁺ antagonist activity.

The method was adapted from Polster P. et al., J. Pharmacol. Exp. Ther. (1990), 255, 593: rings of thoracic aorta were prepared from male Wistar rats (250-400 g) and mounted under an optimal resting tension of 2 g in 10 ml organ baths containing modified Krebs' solution (NaCl 112 mM, NaHCO₃ 25 mM, KCl 5 mM, MgSO₄ 1.2 mM, CaCl₂ 2.5 mM, KH₂PO₄ 1 mM and glucose 11.5 mM, pH 7.4). The bathing solution was maintained at a temperature of 37° C. and gassed with 95% O2 and 5% CO₂. Isometric contractions were measured with a force transducer connected to an amplifier. A computer system was used to control data acquisition and fluid circulation through electrovalves. Drugs were manually injected into the bath.

Each ring was allowed to equilibrate for 60 min in the modified Krebs' solution. Control contractions were repeatedly induced by a depolarising medium (NaCl 17 mM, NaHCO₃ 25 mM, KCl 100 mM, MgSO₄ 1.2 mM, CaCl₂ 2.5 mM, KH₂PO₄ 1.2 mM et glucose 11.5 mM, pH 7.4). After obtaining two reproducible control contractions, a 3rd contraction was induced and the test compound was added to the bathing medium for 2 hours. Only preparation in which the contractions were matched were used. Each tissue received only one concentration of the test compound. Appropriate control experiments were conducted in order to test the effect of the solvant.

To normalize data, the change in tension due to the drug was compared to the change of tension due to the solvant and expressed as percentage of the induced relaxation of the initial contraction. Raw data were processed by a computer system and the pD′2 value was calculated following the method of Van Rossum J. M. et al., Arch. Int. Pharmacodyn. Ther. (1963), 143, 299.

Table C below summarizes the results obtained with the compounds according to the invention. This table shows that none of the tested compounds inhibited the contraction induced by 100 mM KCl on isolated rat aorta. These results suggest that a Ca²⁺ antagonist activity is not to be taking into account for these compounds.

TABLE C Effect of compound on isolated rat aorta contracted by 100 mM KCl Cpd No. Free base/Salt Result 160 2 HCl inactive à 10⁻⁵ M 229 2 HCl inactive à 10⁻⁵ M 230 2 HCl.½ H₂O inactive à 10⁻⁵ M 232 2 maleate inactive à 10⁻⁵ M 233 2 HCl inactive à 10⁻⁵ M 235 2 maleate inactive à 10⁻⁵ M 236 2 maleate inactive à 10⁻⁵ M 237 2 maleate inactive à 10⁻⁵ M 242 2 HCl.½ H₂O inactive à 10⁻⁵ M 243 2 maleate.½ H₂O inactive à 10⁻⁵ M 265 2 HCl inactive à 10⁻⁵ M 281 2 HCl.1/2 H₂O inactive à 10⁻⁵ M 287 2 HCl.1 H₂O inactive à 10⁻⁵ M 295 — inactive à 10⁻⁵ M 297 2 HCl inactive à 10⁻⁵ M 298 2 HCl inactive à 10⁻⁵ M 299 2 HCl inactive à 10⁻⁵ M 300 2 HCl inactive à 10⁻⁵ M 301 2 HCl.⅓ C₃H₈O inactive à 10⁻⁵ M 303 2 HCl inactive à 10⁻⁵ M 304 2 maleate inactive à 10⁻⁵ M 312 2 HCl inactive à 10⁻⁵ M

-   4. Effect of compound on isolated guinea pig ileum contracted by     substance P.

Measuring the effect of compounds in isolated guinea pig ileum stimulated by substance P is a functional test relevant to determine potency of the compounds and nature of the NK₁ antagonism. The method was adapted from Meini S. et al., Neuropeptides (1995), 28, 99: segments of ileum were prepared from male Dunkin-Hartley guinea pig (300-600 g) and mounted under an optimal resting tension of 0.5 g in 10 ml organ baths containing modified Tyrode solution (NaCl 136.9 mM, NaHCO₃ 11.9 mM, KCl 2.7 mM, MgCl₂ 1.05 mM, CaCl₂ 1.8 mM, NaH₂PO₄ 0.42 mM and glucose 5.6 mM, atropine 5 μM, indomethacine 3 μM and chlorpheniramine 1 μM, pH 6.8). The bathing solution was maintained at a temperature of 37° C. and gassed with 95% O₂ and 5% CO₂. Isometric contractions were measured with a force transducer connected to an amplifier. A computer system was used to control data acquisition and fluid circulation through electrovalves. Drugs were manually injected into the bath.

Each segment was allowed to equilibrate for 60 min in the modified Tyrode solution. Control contractions were repeatedly induced by a 30 nM substance P. After obtaining reproducible control contractions, six cumulative concentration-response curves to substance P (0.01 nM to 1 μM) were constructed in the absence or presence of the test compound (incubation time: 30 min). Only preparation in which the control contractions were matched were used. Each tissue received four concentrations of the test compound. Appropriate control experiments were conducted in order to test the effect of the solvant.

Raw data were processed by a computer system and the pD₂, pD′₂ and/or pA₂ values were calculated following the method of Van Rossum J. M. et al., Arch. Int. Pharmacodyn. Ther. (1963), 143, 299 or Arunlakshana O. and Schild H. O., Br. J. Pharmacol. (1959), 14, 48. 

1. An α-arylethylpiperazine of formula I′

wherein Z represents an oxygen atom; n′ represents 1; R² represents a hydrogen atom or a methyl group; W represents (i) a cyclohexyl group substituted by a COOH, or (ii) a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— in which R¹ represents a CN, CONHSO₂alkyl, COOH, COOalkyl, SO₃H, PO(OH)₂, a phenyl group mono-substituted by COOH, a tetrazole of the formula

or a triazolone of formula

X represents a single bond, an oxygen atom or a methylene group; m represents 1 or 2, provided that m is not 1 when X is an oxygen atom; n represents 0, 1 or 2, Ar¹ represents phenyl, a mono-, di- or tri-substituted phenyl group in which the substituents are a halogen atom, an alkyl group, CN or NO_(2;) Ar² represents a substituted aryl group of formula

in which R³ represents a halogen atom or a trifluoromethyl group; p represents 1, 2 or 3; the alkyl groups being linear or branched and having 1 to 4 atoms of carbon, or non-toxic pharmaceutically acceptable salt, individual optical isomer, or individual diastereoisomer thereof.
 2. A pharmaceutical composition comprising a therapeutically effective amount of an α-arylethylpiperazine according to claim 1, or an individual enantiomer, diastereoisomer or non-toxic pharmaceutically acceptable salt thereof, and pharmaceutically acceptable solid or liquid excipient or carrier therefor.
 3. The α-arylethylpiperazine according to claim 1 selected from the group consisting of: [2-(4-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-piperazin-1yl) -ethoxy]-acetic acid; (4-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-piperazin-1-yl -acetic acid; 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic acid; 6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetonitrile; 3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-propane-1-sulfonic acid; 5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-pentanoic acid; (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(3,4,5-trifluoro-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-benzoic acid; {4-[2-(3,5-Dibromo-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-para-tolyl-ethyl]-piperazin-1-yl}-acetic acid; (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethyl)-phosphonic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2,3-difluoro-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2-nitro-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; N-[(2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetyl]-methanesulfonamide; {4-[2-(3,5-Dichloro-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; 5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-2,4-dihydro-[1,2,4]triazol-3-one; 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-4-[4-(1H-tetrazol-5-yl) -butyl]-piperazine; 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-4-[2-(1H-tetrazol-5-ylmethoxy)-ethyl]-piperazine; 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-fluoro-phenyl)-ethyl]-4-[4-(1H -tetrazol-5-yl)-butyl]-piperazine; 1-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-4-[4-(1H -tetrazol-5-yl)-butyl]-piperazine; 1-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-4-[5-(1H -tetrazol-5-yl)-pentyl]-piperazine; (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic acid isobutyl ester; 3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-benzoic acid; and 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-butyric acid; or non-toxic pharmaceutically acceptable salt, individual optical isomer or individual diastereoisomer thereof.
 4. A pharmaceutical composition comprising a therapeutically effective amount of an α-arylethylpiperazine according to claim 3, or an individual enantiomer, diastereoisomer or non-toxic pharmaceutically acceptable salt thereof, and pharmaceutically acceptable solid or liquid excipient or carrier therefor.
 5. A method for the treatment of asthma and/or allergic rhinitis in a patient, which comprises administering to said patient, a therapeutically effective amount of α-arylethylpiperazine of the formula I′

wherein Z represents an oxygen atom; n′ represents 1; R² represents a hydrogen atom or a methyl group; W represents (i) a cyclohexyl group substituted by a COOH, or (ii) a group of formula R¹—(CH₂)_(n)—X—(CH₂)_(m)— in which R¹ represents a CN, CONHSO₂alkyl, COOH, COOalkyl, SO₃H, PO(OH)₂, a phenyl group mono-substituted by COOH, a tetrazole of the formula

or a triazolone of formula

X represents a single bond, an oxygen atom or a methylene group; m represents 1 or 2, provided that m is not 1 when X is an oxygen atom; n represents 0, 1 or 2, Ar¹ represents phenyl, a mono-, di- or tri-substituted phenyl group in which the substituents are selected from a halogen atom, an alkyl group, CN or NO_(2;) Ar² represents a substituted aryl group of formula

in which R³ represents a halogen atom or a trifluoromethyl group; p represents 1, 2 or 3; the alkyl groups being linear or branched and having 1 to 4 atoms of carbon, or an individual enantiomer, diastereoisomer or non-toxic pharmaceutically acceptable salt thereof.
 6. The method of claim 5 wherein the arylethylpiperazine of formula I′ is selected from the group consisting of: [2-(4-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-piperazin -1-yl)-ethoxy]-acetic acid; (4-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-piperazin-1-yl)-acetic acid; 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-cyclohexanecarboxylic acid; 6-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-hexanoic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetonitrile; 3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-propane-1-sulfonic acid; 5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-pentanoic acid; (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]piperazin-1yl}-ethoxy)-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(3,4,5-trifluoro-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-benzoic acid; {4-[2-(3,5-Dibromo-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-para-tolyl-ethyl]-piperazin-1-yl}-acetic acid; (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethyl)-phosphonic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2,3-difluoro-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(2-nitro-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; N-[(2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetyl]-methanesulfonamide; {4-[2-(3,5-Dichloro-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-acetic acid; {4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-cyano-phenyl)-ethyl]-piperazin-1-yl}-acetic acid; 5-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-ylmethyl}-2,4-dihydro-[1,2,4]triazol-3-one; 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-4-[4-(1H-tetrazol-5-yl) -butyl]-piperazine; 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)1-phenyl-ethyl]-4-[2-(1H-tetrazol-5-ylmethoxy)-ethyl]-piperazine; 1-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-(4-fluoro-phenyl)-ethyl]-4-[4-(1H -tetrazol-5-yl)-butyl]-piperazine; 1-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethoxy]-1-phenyl-ethyl}-4-[4-(1H -tetrazol-5-yl)-butyl]-piperazine; 1-{2-[1-(3,5-Bis-trifluoromethyl-phenyl)-ethyl]-1phenyl-ethyl}-4-[5-(1H -tetrazol-5yl)-pentyl]-piperazine; (2-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazin-1-yl}-ethoxy)-acetic acid isobutyl ester; 3-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazine-1-ylmethyl}-benzoic acid; and 4-{4-[2-(3,5-Bis-trifluoromethyl-benzyloxy)-1-phenyl-ethyl]-piperazine-1-yl}-butyric acid; or non-toxic pharmaceutically acceptable salt, individual optical isomer or individual diastereoisomer thereof. 